The Trace Specialist

The role of the Senior Scientist in Forensic Science in the UK today

2011-12-31T16:20:00.009Z

Over the years a succession of successful cold case reviews have seen police and forensic scientists working at close quarters with each other to a different level than usually seen in 'live' cases. The experiences of the police in conducting these reviews at the laboratory level with scientists has put the spotlight onto the roles of the senior scientist, the laboratory practitioners and the investigators themselves. The success of these cold cases appears to have been some kind of pyrrhic victory for the senior scientists, successfully solving cold cases at the cost of showing the police how to do it.

A question often posed by those seeking to understand issues that have arisen in past cases so as to improve current and future practices is whether the setting of forensic strategy and the prioritization of exhibit examinations requires a skill that only senior forensic scientists possess? What by way of scientific knowledge makes a scientist more effective at this process than anyone else (such as an investigator for instance) and what precise scientific method are we using to determine which exhibits we should examine, for what and in what order? If the answer is that we read the case circumstances provided by the police, roll the dice and take our chances that is arguably no more scientific than the police sending in items and asking the lab to 'forensicate' the case.

The police, it would appear, have made up their own mind. In most forces the role of deciding forensic strategy and exhibit prioritization rests with scientific support functions internally. That is not to say that the police do not seek scientific advice from the forensic scientists regarding strategy etc, of course they do and in my experience, they more often than not seek out advice so as to make an informed choice. But it is a fair reflection of the status quo in the UK to say that it is the police who ultimately decide on the strategy and priority of exhibit examinations, and they do so whilst working under budgetary constraints.

Other forces have taken it to another level entirely, performing the strategy setting and prioritization functions of the senior scientists themselves - whether by employing scientists or utilizing other in-house functions, but also employing laboratory level practitioners to process exhibits - only really drawing the line at performing the analysis of samples (such as DNA etc) themselves. The economic argument for them doing so in-house, rather than utilizing the established external forensic provider market has not been published. Given the costs of not only employing scientific staff but also investing in facilities and the costs of gaining accreditation, it is doubtful that the economic argument will turnout to be persuasive for in-force provision compared to seeking a competitive rate in the external market - at least in the short term, but that would be largely missing the point. The point is that some of the police forces have seen how complex casework is done and they believe that they can do at least as good a job themselves in-house and that appears to be enough for them to consider that in-force provision is the way forward.

Whatever happens in the future, the market paints a bleak picture for the future role of the senior scientist.

Validation, Validation, Validation - what now for forensic R&D?

2010-11-03T09:13:00.013Z

In the wake of recent court judgements (R-v-Hoey and the subsequent enquiry, followed by the judgement in R-v-Reed) and the publication of the Regulator's draft codes of conduct which attempts to define validation, the issue over whether or not a technique / process has been validated continues to cause utter confusion.

In R-v-Hoey the issue over whether or not the process used by the FSS in dealing with low-template DNA analysis (LCN or "Low Copy Number" as used by the FSS) was scrutinised comprehensively, and challenged by the defence team on the basis that it was not a valid process.

The FSS stated that they had put LCN through their own validation processes including the publication of the method in peer reviewed journals. Furthermore the FSS had been through several rounds of accreditation (inspected by UKAS) during which the process of LCN would have been explored in detail.

The court held that this was not enough and ruled that:

"...However, in the case of LCN there is no validation other than the assertion by Drs Gill and Whitaker that two published journal papers they had written amounted in effect to peer review and thereby the necessary validation, a proposition which was strongly disputed by the Defence experts..."

A government enquiry - held in the aftermath of the judgement held that:

"...we find that the science supporting the delivery of Low Template DNA (LTDNA) analysis is sound and that the three companies (the Forensic Science Service Ltd, LGC Forensics and Orchid Cellmark Ltd) providing this service to the Criminal Justice System have validated their processes in accord with accepted scientific principles using both 28 and 34 PCR cycles for extracts containing less than 200 picograms (pg) of DNA."

In R-v-Reed the court went further and stated that:

"...On the evidence before us, we consider we can express our opinion that it is clear that, on the present state of scientific development:

i) Low Template DNA can be used to obtain profiles capable of reliable interpretation if the quantity of DNA that can be analysed is above the stochastic threshold – that is to say where the profile is unlikely to suffer from stochastic effects (such as allelic drop out mentioned at paragraph 48) which prevent proper interpretation of the alleles.

ii) There is no agreement among scientists as to the precise line where the stochastic threshold should be drawn, but it is between 100 and 200 picograms.

iii) Above that range, the LCN process used by the FSS can produce electrophoretograms which are capable of reliable interpretation. There may, of course, be differences between the experts on the interpretation... However a challenge to the validity of the method of analysing Low Template DNA by the LCN process should no longer be permitted at trials where the quantity of DNA analysed is above the stochastic threshold of 100-200 picograms in the absence of new scientific evidence..."

So at the end of an internal validation by the supplier, several rounds of UKAS accreditation and inspections of the supplier during which the technique was in use, two appeals and a government enquiry, it is the appeal court which drew a line at above 200 picograms here - not the scientists, and not the government.

So how exactly can a method or process used in forensic science be deemed valid? Internal process do not seem to be enough, nor does publication in a peer reviewed journal, nor does an accreditation of the system (of which the process is a part) to a national standard and nor does an independent review of the science by the government suffice. Right now, it is the court that is deciding whether or not a process is valid and furthermore it is defining the analytical levels at which that validity can be challenged.

The regulator demands that providers be accredited to ISO17025 (to be replaced by the forensic standard in due course). Either way, these standards demand validation of processes. UKAS require documented evidence of the technique used in casework so that they can grant accreditation. So in order to bring in new science to forensic science, the supplier must bear the risk of introducing it to casework without it being assessed against the standard in the first place.

Commerical forensic science providers now have to weigh up the probability that their R&D would survive a challenge in court - and if the R&D failed, what the impact on their business might be. It is not just the money that is invested in R&D, it is not just the business that you might win on the basis of the new R&D, it is also the business that might be lost if the court rules against it and/or limits its use or scope. For some suppliers that might be cause enough to close down any R&D programmes that still exist - and who could blame them for that?

Now is not a good time to be doing R&D in forensic science in the UK.

The Bayesian Approach - How are we Doing?

2010-05-19T00:56:00.027+01:00

Much has been written about how Bayesian interpretation can be applied to different evidence types over the last fifteen years, and lately there have been attempts to adopt the approach right the way through the forensic process, in some cases even starting before items are submitted, and in other cases ending with the scientist making up a defence scenario on behalf of the defendant.

Here in the UK, the Forensic Regulator has recommended that accreditation to 17025 (and further to a new forensic standard to be published in due course) is the only standard that forensic laboratories need. The Forensic Regulator was also of the view that individual practitioners employed by organisations who hold the standard do not need anything further, as merely by virtue of their employers status as an accredited laboratory this ensures their competence.

Part of the 17025 standard requirement is for proficiency testing to occur on a regular basis. If the test is externally administered it is considered to be an excellent means of evaluating the performance of a laboratory and by implication it is a measure of the laboratory systems and the competence of its staff.

There are very few commercial providers of forensic proficiency testing in trace evidence in the world. The oldest and most accepted is CTS in the US. They produce and administer proficiency tests over a wide range of evidence types every year. A report on each test is produced and published, the identities of the laboratories are kept anonymous by means of assigning each lab a unique code.

The CTS fibre proficiency test tends to follow a set format that tests the laboratory's ability to identify and compare fibres from three samples. For this part of the test there are three possible outcomes either the samples match, don't match, or the findings are inconclusive. In reality, for laboratories undergoing the test there are only two outcomes - either you get it right or you get it wrong. Get it right and the lab's systems are deemed in good working order, and its staff are deemed competent (at least those who took the test anyway), get it wrong and the accredited lab has to investigate and take action according to their process. Getting it wrong is as serious an issue as it gets for an accredited lab and its staff.

The second part of the test is of general interest but does not count as a proficiency in real terms because there is no expected outcome. The participant lists the techniques used and their conclusions. There is no right or wrong answer for these and the participants are under no obligation to enter any data at all here.

This year's report on the fibre proficiency test 10-539 has just been published. As all accredited laboratories in the UK are likely to have performed this test, and how all are likely to have used the Bayesian approach, the publication of the report provides an opportunity for an assessment of how labs interpret fibre evidence in this way. Each lab appears to have got the same (correct) scientific result with respect to the matching fibres and all were given precisely the same information.

The scenario given was straight forward, a sample from the inner lining of a jacket, and two clumps of fibres, one found on the inner door latch on the passenger side of a truck, the other on the driver's seat of the truck. After testing, only the clump on the inner door latch was found to be indistinguishable from the lining of the jacket.

Here's the conclusions that had Bayesian elements from this year's test, they can't all be right, you can decide which approach you like best:
Lab 1

Door latch on the passenger side of the suspect's truck: Orange polyester fibres (item 2) of two types, indistinguishable from the two types of polyester fibres used in construction of the jacket lining (item 1),were found on the inner door latch on the passenger side of the suspect's truck. In interpreting the scientific findings I have considered two alternative propositions: The jacket lining (item 1) had been in contact with the inner door latch on the passenger side of the suspect's truck. The jacket lining (item 1) had not been in contact with the inner door latch on the passenger side of the suspect's truck and the polyester fibres originated from another item(s) constructed of the same two types of indistinguishable orange polyester fibres. In my opinion, the scientific findings provide strong scientific support for the former proposition rather than the latter. In expressing the evidential significance of my findings, I have used the following scale: no scientific support, limited, moderate, moderately strong, strong, very strong and extremely strong scientific support. Driver's seat of the suspect's truck: In my opinion, the fibres (item 3) recovered from the driver's seat of the suspect's truck did not originate from the lining of the jacket (item 1).

Lab 2

I have considered the following propositions for the finding of the orange polyester fibres of two types (item 2) indistinguishable from the two types of polyester fibres that comprised the lining of the victim's jacket (item 1) on the inner door latch of the passenger side of the suspect's truck: The victim had been inside the vehicle and fibres were transferred from the victim's jacket to the door latch. The victim had not been inside the vehicle and the fibres found originated from another item(s) composed of the same two types of indistinguishable fibres. In my opinion, the findings provide strong scientific support for the former proposition rather than the latter. In my opinion, the fibres recovered from the driver's seat (item3) did not originate from the lining of the victim's jacket.

Lab 3

These findings provide very strong support for the suggestion that the fibres from the inner door latch on the passenger's side of the suspect's truck came from the inner lining of the victim's jacket. These findings show that the fibres from the driver's seat of the suspect's truck did not come from the inner lining of the victim's jacket. I have chosen the above phrases from the following scale; weak support, moderate support, moderately strong support, strong support, very strong support and extremely strong support. The conclusion was addressed at source level due to the limited samples received. In a case situation the jacket and further samples from the truck would have been available, in which case the activity level
could have been addressed.

Lab 4

The orange polyester fibres of Item 2 were indistinguishable in terms of their microscopical appearance and colour from the orange polyester fibres used in the construction of Item 1. In assessing the laboratory findings and drawing my conclusions, I have considered the following two alternative propositions: The fibres recovered from the inner door latch of the passenger side of the truck, Item 2, originated from the inner lining of the jacket, Item 1. The fibres recovered from the inner door latch of the passenger side of the truck, Item 2, did not originate from the inner lining of the jacket, Item 1. In my opinion, the laboratory findings are more likely if the first proposition were true rather than the second alternative. In my opinion, the laboratory findings provide very strong scientific support for the proposition that the fibres recovered from the inner door latch of the passenger side of the truck, Item 2, originated from the inner lining of the jacket, Item 1.

Lab 5

Sixteen fibres from the driver's seat (Item 3) was recovered for examination by comparison microscopy. No fibres matched the component fibres of the jacket inner lining (Item 1). Sixteen fibres from the inner door latch (Item 2) were recovered for examination by comparison microscopy. A sample of these fibres were further analysed by microspectrophotometry and infrared spectroscopy. All were indistinguishable from the component fibres of the jacket inner lining. These findings would support the proposition that there had been direct contact between the inner door latch and the lining of the jacket.

Lab 6

In our opinion, orange polyester fibres from a yarn recovered from the passenger side inner door latch of the suspect's truck (Item 2), correspond to the orange polyester fibres of the victim's inner jacket lining. In addition, the presence of the orange polyester fibres in the form of a yarn, in our opinion, means that it must have been shed from a damaged garment, such as the victim's jacket. In assessing the evidential significance of these findings, we have considered two possible explanations for the matching fibres: (1) The yarn of orange polyester fibres from the passenger side inner door latch of the suspect's truck, is from the inner lining of the victim's jacket; Or, (2) The yarn of orange polyester fibres from the passenger side door latch of the suspect's truck is NOT from the inner lining of the victim's jacket, but originates from another damaged garment that sheds yarns that happen to match the orange polyester fibres of the jacket lining by coincidence. In our opinion, the orange polyester fibres of two types found on the passenger side door latch of the suspect's truck are relatively uncommon. The presence of these two fibre types matching the inner lining of the victim's jacket in our opinion provides greater evidence of a link between the victim's jacket and the passenger side inner door latch of the suspect's truck, than would have been the case with an apparent transfer of a single fibre type alone. Therefore in our view this makes the first explanation for the findings far more likely than the second. In our opinion, the fibre transfer evidence therefore provides strong scientific evidence of a link between the victim's jacket and the inner door latch on the passenger side of the suspect's car. No fibres matching the component fibres of the victim's jacket lining were found within Item 3.

Lab 7

The findings in this case, and the information provided, have been used to address the following propositions: a) The damaged lining of the victim's jacket has been in contact with the inner door latch of the suspect's vehicle. b) Some other item left the fibres on the inner door latch of the suspect's vehicle and any matching fibres recovered are due to chance. Taking the results of the examinations in this case together with published studies and casework experience, in my opinion, the likelihood of finding two distinct fibre types of an orange colour randomly in the population is fairly low. In addition, given that these fibres would shed only due to the lining being damaged, that there are two distinctly different fibres comprising the warp and weft of the fabric, and that both of these fibre types were recovered from the inner door latch and are found to be indistinguishable in terms of colour, dye and chemical composition, to the polyester fibres of the warp and weft of the jacket lining then, in my opinion, there is very strong support for the view that the damaged lining of the victim's jacket has been in contact with the inner door latch of the suspect's vehicle rather than the fibres transferred originating from some other item by chance. The term "very strong support" is selected from a scale of standard terms used to express the relative level of scientific support for a proposition over its alternative, as discussed above. These terms are: Limited, Moderate, Moderately Strong, Strong, Very Strong, Extremely strong Additionally, in some instances, a proposition may be conclusively supported, if the findings are such that the alternative can be dismissed. If the findings provide no greater support for one proposition over the other, then the findings are described as inconclusive. My interpretations and conclusions are based on the background information available to me at present. If any of this information changes, or is found to be incorrect, then I may need to reassess my findings.

Lab 8

Item 1 comprised a square of orange fabric with one glossy side and one matte side. The fabric was composed of orange, delustered, polyester warp fibres with hexagonal cross section and orange, non-delustered, trilobal polyester weft fibres woven together to form a 2:1 twill. Item 2 comprised orange, delustered, polyester fibres with hexagonal cross section. These fibres corresponded in appearance, composition and colour with fibres from the warp threads in Item 1. The results support the proposition that the fibres recovered from the inner door latch on the passenger side of the suspect's truck shared a common origin with the known section of fabric from the inner lining of the victim's jacket (Item 1). Item 3 comprised orange, multilobal acetate fibres. These fibres differed in appearance, composition and colour with the fibres from Item 1. The results do not support the proposition that the fibres recovered from the driver's seat of the suspect's truck shared a common origin with the known section of fabric from the inner lining of the victim's jacket (Item 1)

Lab 9

The sample from the victim's jacket (item 1) contained two types of orange polyester fibres. The sample from the inner door latch of the suspect's truck (item 2) contained two types of orange polyester fibres. These fibres could not be distinguished from the fibres from the victim's jacket (item 1) by microscopy, colour comparison and infrared spectroscopy. The sample from the driver's seat of the suspect's truck (item 3) contained orange acetate fibres. These fibres were different to the fibres of the victim's jacket (item 1) and therefore are not from the victim's jacket. In my opinion the scientific evidence strongly supports the proposition that the fibres from the inner door latch of the suspect's truck (item 2) are from the victim's jacket (item 1). I have chosen the term "strongly supports" used in describing the scientific evidence above from the following scale of terms: inconclusive, slightly supports, supports, strongly supports, very strongly supports and conclusive.

Lab 10

The forensic significance of fibres is partly dependant on the number of fibres present, and how common that fibre type and/or colour is in textile manufacturing. The fabric in Item #1 was constructed from two different types of orange polyester fibre. The orange polyester fibres from Item #2 were indistinguishable from one type of the fibres in Item #1. The number, colour and length of the fibres present strongly supports the hypothesis that the fibres in Item #2 originated from the same source as Item #1. The fibres in Item #3 were different to those from Item #1 and, as such, could not have originated from the same source.

Lab 11

Based on visual, chemical and colour analysis the two types of orange polyester fibres recovered from the inner door latch on the passenger's side of the suspect's truck (item 2) could have come from the inner lining of the victim's jacket (as represented by item 1), or from a textile containing fibres with the same visual, chemical and colour features. Based on visual, chemical and colour analysis the fibres recovered from the driver's seat of the suspect's truck (item 3) could not have come from the inner lining of the victim's jacket (as represented by item 1). In my opinion, this fibre evidence supports the proposition that the inner lining of the victim's jacket (item 1) came into contact, either directly or indirectly, with the door latch on the passenger's side of the suspect's truck. Note that as fibres are mass produced another source of fibres with the same visual, chemical and colour is possible.

Some use two propositions, some using one, some using scales of support some not. Some attach a very strong level, others a strong level, others no level at all. Some place the victim inside the vehicle, others include the possibility of indirect transfer. Some used different scales. Some believe that the scientific findings can be used to show support for the fibres coming from the victim's jacket rather than any other item made of fibres indistinguishable to it, others believe that the scientific findings can be used to show support for the fibres coming from the victim's jacket rather than via contact with any other item by chance. These are not the same propositions.

But what is clear is that given the same scenario and the same results, that the approach to Bayesian interpretation of fibre evidence varies widely from one laboratory to another, and by implication, one scientist to another. These issues are not unique to fibre evidence. Using Bayesian interpretation as a standard approach in this way does provide a common language for us as forensic scientists to communicate our findings. We just don't seem to be very good at it. It would appear that the common language does more to separate us than unite us.

Is it a matter of competence of the individual, the system of peer review, or a cultural approach by the laboratory? Either way, current quality systems do not address it. But perhaps this is where the regulatory line should be drawn, and that the courts, not the regulatory bodies, are better placed to test matters of individual opinion, after all it is the individual scientist, not the organisation that employs him that is on the stand.

The end of an era: Ken Wiggins and Mike Grieve

2009-12-29T20:34:00.006Z

It was with great sadness that 2009 marked the passing of Ken Wiggins. Together with Mike Grieve (who passed away in 2002), they will be sorely missed by all who knew them.

Ken and Mike were very well known in the global Forensic Fibre community. Pioneers in the field of fibres, the numerous papers they published on the topic of forensic fibre examination will be a legacy that will endure. However, perhaps their greatest contribution to forensic science was in their partnership with the foundation of the European Fibre Group (EFG), a group Ken was to lead as president (until he retired in 2006).

History can sometimes reduce the impact of an individual to a chronology of milestones but as always its the stuff inbetween that really matters. Ken and Mike were professional at all times and they shared a vision for the EFG that carried the group forward. The emphasis on Research and case studies that formed the basis of the EFG meetings pre and post ENFSI, made the group distinctive and served to raise the standard of forensic fibre work via a combination of education and encouragement. This was largely down to the tone set by Ken and Mike. They worked hard, and worked the group hard, but they could let their hair down afterwards and compete with each other the next morning as to who could look the least hungover. Together they achieved a lot, and both will be missed by all who knew them.

A new era for Forensic Fibre Examination is beginning in the backdrop of emerging new EU regulations in Forensic Science and emerging markets. It will be interesting to observe how well the EFG will adapt to the new challenges ahead.

Spectroscopic analysis of body fluids - update

2009-12-22T16:05:00.009Z

Raman spectroscopic signature of semen and its potential application to forensic body fluid identification, this paper was recently published in FSI and is an update on the ones from last year (Raman spectroscopy offers great potential for the nondestructive confirmatory identification of body fluids and Analysis of body fluids for forensic purposes: From laboratory testing to non-destructive rapid confirmatory identification at a crime scene). This study, more indepth than the previous ones and focussing on semen, identified three key indicating components of interest from a raman spectrum that can be used to identify a semen sample. However, there were several contributing species (shown in the spectrum below) that made up the three components namely:

Tyrosine (peaks in green)
Albumin (peaks in blue)
Choline (peak in yellow)
Spermine phosphate hexahydrate (peaks in purple)

The potential for being able to identify dried semen on tapings using a confocal approach, would appear to be possible, particularly useful for old (cold) cases where the items of clothing may no longer be available.

One slight concern was the strength of the laser used to obtain the data in the paper. 115mW seems like a lot for a biological sample which you would not wish to heat. No attempt was made to assess the impact of the technique on any DNA process after analysis so its not a validation of the process for forensic use, but its a step in the right direction.

Fibre papers published 2009

2009-12-22T14:34:00.006Z

There were several papers published in 2009 on fibres. Some of these are considered below in no particular order.

The population, transfer and persistence of fibres on the skin of living subjects was published in Science and Justice. Papers that deal with the difficult issue of fibre persistence are always of great interest because of the complexities involved in the subject. This paper did a good job of converting theoretical knowledge of fibre transfer and persistence into casework situations involving exposed skin and provided a scientific basis for assessing fibre populations on skin. Scene-going scientists would benefit from understanding the data as it would assist in their evaluations of the potential for fibre recovery.

The kinetics of colour change in textiles and fibres treated with detergent solutions: Part I—Colour perception and fluorescence microscopy analysis and The kinetics of colour change in textiles and fibres treated with detergent solutions: Part II — Spectrophotometric measurements both published in S&J. Fibres that have been washed could theoretically appear different under the microscope owing to the contribution from the detergent. This not only could affect items of clothing submitted as reference samples (so that the reference sample is different from any at the scene), but populations of fibres on clothing (so that any potentially linking recovered fibres appear to be different). These papers describe in detail the types of changes that could occur for several different fibre types at the microscopic and chemical levels. The papers serve as good background information and as a reminder to fibre examiners to question and challenge what they see down the microscope.

Automotive flock and its significance in forensic fibre examinations this was one of our papers and was a study that came directly from our casework experiences.

The application of laser scanning confocal microscopy to the examination of hairs and textile fibers: An initial investigation this paper, from Forensic Science International, showed that the LCM technique produces some excellent images of fibres in terms of their cross section and gave some valuable pointers for optimizing conditions for capture. LCM is a technique that at present is not widely available to all. The non-destructive aspect of the capture of the image is most appealing, although when compared to the cheap alternatives (such as cutting the fibre) it is a luxury.

The Analysis of Metameric Blue Fibers and Their Forensic Significance , this paper focussed on metamerism and demonstrated that even though samples are metameric - they are likely to be distinguishable via their UV-VIS-NIR spectra. This study may seem obvious, but it was an important point.

Pseudo Science in Forensic Submissions

2009-12-02T15:18:00.015Z

The following information has been taken directly from a document published on a police force website, some adjustments have been made to preserve anonymity:

Volume Crime - Research shows that outside the ‘core evidence’ types of DNA, fingerprints and footware [sic], very little success is gained from laboratory examinations of other types of materials, eg glass, fibres etc.

What research? No reference to any publication is made in the document.

The general principal will be that there will be no forensic examination made of any items where ;-
1. There is little likelihood of the offence being detected.
2. The examination will only produce corroborative evidence, unless it can be shown that the forensic evidence will enable a person to be charged with an offence.
3. In cases where a suspect is arrested more than 8 hours after the offence was committed, or the clothing was seized after that lapse of time even though the suspect was in custody, and the potential evidence relates to paint, glass, fibres or firearms residues.

Are these magic traces that spontaneously decompose after 8 hours or perhaps the laws of physics cease to exist in police investigations?

Of course a police force has finite a budget and that decisions have to be made as to how that money is best spent, but this is utter nonsense - dressed up as science. Make the policy, define the criteria for forensic submissions but don't attempt to justify it on scientific grounds unless the science is properly understood and applied correctly.

Forensic submissions are expensive. All forensic submissions need to be examined for their cost effectiveness.

Forensic submissions cost money - of course they do, but to describe them as expensive is unfair. Are forensic submissions more expensive than the cost of running 43 police forces in England and Wales? The United States has about the same number of state police forces and they have to cover 40 times the geographical area and five times as many people.

If this government (or any future one) is serious about balancing the public books and fighting crime, that's the place for big savings to be made - not cutting forensic submissions. After all its what the police want

Learning to live with the CSI effect

2009-11-24T09:07:00.016Z

Over the years much has been made of the CSI effect . Usually it's forensic scientists, lawyers and police who slam the media for raising the expectations of forensic science in the eye of the public. The show "CSI" appears to take much of the blame for this, I'm sure much to their producer's delight.

As a piece of entertainment, CSI is alright. Its just hard for those who work in the field of forensic science to watch it, because we're too busy screaming at the television to tell them to switch the lights on.

What is interesting to observe in the media is the number of everyday stories where claims are made about forensic science where forensic scientists, lawyers or police are not shy about talking of their successes. What these stories have in common is the phrase 'Advances in forensic science' [or variants thereof]:

Detective Chief Inspector Ridley said: "One of the key areas of our work involves working closely with forensic scientists. Advances in forensic science and technology now provide us with the opportunities to detect serious crimes and limit the activities of the most dangerous offenders in society." story

The police are reluctant to identify the cases (as the suspects would know who they were and would doubtless make themselves scarce) but Geoff believes this is the start of a new trend. "Because of the advances in DNA we are going to see more and more double jeopardy prosecutions in the future - which is good because why should killers sleep soundly in their beds?" story

DC Lynn Adams, who led the investigation, said the case should serve as a warning to those who think they have got away with crimes.

She said: “Bedfordshire Police are using every tool at their disposal to fight burglary and this is another good example of how advances in forensic science can help us.” story

Certainly the police appear to be more than happy to add to the "dream that is CSI" when it works well. When it doesn't work so well, the forensic scientists find themselves largely on their own...

Commander Dave Johnston, head of homicide and serious crime at the Met's Specialist Crime Directorate, said: "We are of course concerned that the new forensic evidence heard in this trial was not available for the first investigation and sympathise with the anguish that this may have caused to those affected.
"Now the trial process has concluded it is important that the answers are found as to how this forensic evidence was missed so that the public and the courts can maintain their confidence in forensic science. story

Pride leads to anger, anger leads to fear, fear leads to ....
DNA evidence can be fabricated and planted at crime scenes, scientists warn story . But British experts said it was highly unlikely any criminal would go to such lengths. Dr Gill Tully of the Government-funded Forensic Science Service said: 'You would need a full molecular biology lab, thousands of pounds worth of equipment and a fully competent molecular biology scientist or technician. 'The vast majority of people who may be involved in criminality would not have access to these materials.'

Hmmm.....the minority of well funded and innovative criminals on the other hand...

My point is that we can't blame a TV show for the public perception of forensic science, because all those who have a stake in the criminal justice system (and that's everyone who pays taxes) participate in the media one way or the other, either in making the stories or by reading them. If we are to blame CSI, we must also blame ourselves.

Shows like CSI are a fantasy, not unlike Star Trek. But the ideas expressed in Star Trek have been credited with inspiring inventors from Stealth Technology (the cloaking device) to the mobile phone (the tricorder). Perhaps there are elements in the forensi-tainment shows that could inspire us to live up to the expectations they generate, although we might have to stop screaming at the television to see them.

Another year in the market....

2009-11-17T09:00:00.006Z

2009 will be remembered as the year that the forensic landscape in England and Wales changed dramatically. The announcement of the closure of the FSS labs in Chepstow, Chorley and Birmingham, appears to draw a line right down the middle of the country. If the forensic market is considered to be a black and white battle between the government and the private sector ("good" and "evil" in the eyes of some commentators), it can be roughly seen (with no little irony) that the government are on the right hand side and that the private sector are on the left, perhaps this a portent of next year's general election result?

Given the changes of the past decade, reform of the FSS was inevitable. It can be certainly argued that if the FSS had taken the threat of an emerging private sector more seriously ten years ago perhaps changes could have been implemented that could have saved the three sites and the jobs and skills that go with them. But traditionally, the public sector is not the place where change comes easily, and ultimately the market lost its patience. Whatever will be said of 2009 in the years to come, perhaps it will be best remembered as the year that finally killed off the notion that the presence of a lab local to a police force is an advantage in a modern forensic marketplace.

Why is that? Well the police are doing more work themselves - of that there is no doubt. If the demand for crime scene attendance by scientists is met internally within forces, there is no real need for a local lab to get scientists to a scene quickly. Is the quality the same? Perhaps, perhaps not, it depends on entirely on their qualifications, training, experience and competence. This of course is a matter for the regulator and the police forces, but whilst the police demand forensic providers to be accredited, yet perform themselves without needing to demonstrate the same commitment (investment) in quality, there is inequity here. If the regulator sees his reforms through, Police Forces will not be allowed to continue to provide internal services without accreditation, but when will they have to comply - it doesn't appear to be anytime soon going on the pace of this year's push for reform. If in the meantime a Force decides not to pursue accreditation internally on a cost basis, whilst being locked into a 3-5 year contract with a provider on the other side of the country, they may find themselves without a local lab to turn to for help.

Interestingly the major players in the market appear to be adopting different strategies - which has to be viewed as healthy for all. With LGC up for sale and with sale of the FSS to follow (if you believe the Daily Mail: http://www.dailymail.co.uk/money/article-1222702/Forensic-Science-Service-set-sale.html ), together with the scramble for the remaining regional tenders makes it look like 2010 will be another interesting year in the market.

One standard to rule them all...

2009-03-17T21:24:00.025Z

One standard to find them, One standard to bring them all and in the darkness bind them....

Of course regulation of the forensic market is the right thing to do and is something that is long overdue.

The forensic regulator has recently recommended that one body be responsible for accrediting forensic science providers so that they can supply the Criminal Justice System. The regulator also believes that organisational accreditation combined with the adoption of national occupational standards is the standard required and that if a provider achieves that standard, there is no further need for individual scientists to have their competence assessed by any body external to their own organization. From inside the industry looking out, this looks like a real case of the cobbler wearing the worst shoes.

The regulators plans are, in many ways, quantum leaps forward from where we were ten years ago prior to the formation of CRFP. The focus on organizational quality is important because, at least in theory, it should make it much more difficult for the likes of Gene Morrison to operate, and that is most welcome. However, the issues with institutional forensic science in high profile cases in recent years have not been focussed on organizational failings, but on individual scientists.

The enquiry into the forensic investigation in the case of Damilola Taylor concluded that :"...there was no systemic failure in the operations of the FSS; there were however human failures in implementing operating procedures". It went on to recommend widening the scope of the external assessment of competence of individuals as a means of addressing these human failures. So why has the regulator made recommendations removing external means of assessing individuals from the entire quality structure?

The regulators recommendations address only the institutional element of quality. It is not enough. If quality in forensic science provision means only adopting institutional quality and occupational standards alone without a system for the external measurement of competence of the individual scientist, the profession will be thrust back into the past. Back then some providers were accredited to the relevant BSI standard and the employers certified their own scientists competence internally. It was precisely the environment in which the failures in the Damilola Taylor investigation occurred - so how do the new proposals ensure that this won't happen again?

We have an opportunity to lay the foundations for better forensic science provision to the CJS. It must include transparent, discoverable, external assessment of individuals to move us all forward.

Otherwise we will find ourselves back to where we started, all bound together in the darkness...

Spectroscopic analysis of body fluids

2008-12-23T09:38:00.007Z

2008 appeared to be the year for spectroscopists attempting to assist our colleagues in forensic biology. Two papers caught our eye, both published in Forensic Science International.

"In search of blood - Detection of minute particles using spectroscopic methods" described in detail the different morphological appearances of blood particles on tapings. This hadn't been done before and was very interesting. The authors proceeded to show how particles of blood can be identified using a combination of MSP and raman spectroscopies, the advantage being that the analysis is performed in-situ and non-destructively. One question that does arise is whether or not the analysis would have had a detrimental effect on DNA recovery later - which was not explored in this study. Our own experience with raman technologies would suggest that it is unlikely to have any detrimental effect.

The current method for identification of blood in tapings appears to be to use the same presumptive test as is used for the identification of blood on clothing etc. Expose the surface of the blood fragment, rub a piece of pointed filter paper on the surface, apply your chemical treatment to the paper and observer the colour change. It is a very sensitive test, and my colleagues in forensic biology are confident that it would detect very small fragments and it has been used successfully in the past.

On the other hand the chemical test relies on a physical interaction between the blood and the paper so that sufficient material is transferred to the filter paper. The presence of the glue matrix could interfere with this process, although perhaps not for bigger particles where sufficient contact could be made.

So when would you consider tapings as a source of tiny blood fragments? Perhaps in these situations, where:

the surface of the item is particularly smooth and the standard blood search is negative
the item of clothing itself is no longer available but tapings taken from the item are present - such as cold cases

The authors specifically mention cases where items have been washed but where minute particles in low numbers may remain undetected by the standard protocols. This may seem to be unlikely, but studies on sperm have shown that sperm can be transferred from one item of clothing to others whilst being washed in a machine. Enzymatic activity of the particles, on which the presumptive tests would rely, could have been destroyed, leaving particles of blood undetectable by the presumptive tests on the clothing.

The best thing about this study is that it provides forensic scientists with more options when considering complex questions - such as is there blood on this item? After all, if the Damilola Taylor case has taught us anything, it is that we can't take a negative blood screen for granted.

The second paper "Raman Spectroscopy offers great potential for the nondestructive confirmatory identification of body fluids" described the analysis of body fluids to ascertain whether or no they could be uniquely identified. Semen, Vaginal fluid, saliva, sweat and blood were all analysed. This preliminary study shows that each type of body fluid bears its own raman signature, however as the study used only single samples of each body fluid for analysis, the results should be treated with some caution. One very interesting result was the presence of thiocyanate in saliva which did not appear in any other body fluid.

Fibre papers published 2008

2008-12-22T16:05:00.015Z

This post is a review of selected papers published in 2008 in which trace evidence and/ or spectroscopic analysis were applied to issues of interest to trace evidence examiners.

Overall, 2008 was an average year for papers published in trace evidence. By far the majority of these papers were published by forensic science laboratories, or as a result of a collaboration between forensic science labs and other institutes. Considering the number of universities actively engaged in forensic science education globally, one could be forgiven for wondering what it is they are doing research in, whatever it is - it doesn't appear that trace evidence is high on their agenda - for whatever reason.

Starting first with fibres, Science and Justice published two papers on fibres this year, which is not bad for a journal that only publishes quarterly and with only a handful of scientific papers in each edition.

The first paper "Application of Raman Spectroscopy to forensic fibre cases" described the casework experience of one laboratory applying raman routinely in fibre cases. Five case studies were described and it was clear that the opinion of the authors were that using raman routinely in fibre cases was a valuable thing to do. However, on one crucial point the message as to precisely how the technique provided additional discrimination for mauve nylon fibres beyond MSP analysis was not clear, the reader can only speculate that the precise identification of the dye, and not merely the comparison of coloured fibres, is the source of the author's opinion that evidential value of the association was increased.

The practical advantages of raman as a laboratory technique are stated clearly, and recommendations as to how to get the best spectral data from fibres in difficult matrices are most welcome.

The second paper "The discrimination of (non denim) blue cotton", at first glance, appeared to be a repeat of work done by Biermann et al, which, somewhat bizarrely, was published in the same journal, in 2007 (The evidential value of blue and red cotton fibres, Science and Justice 47 (2) 2007). Biermann's study was a comprehensive treatment of the majority of the work done here, a fact acknowledged by the authors very early in the text. Most researchers in their career, have had experience of being beaten to the publishers desk by another research team, and this appears to be the case here.

The message given by Biermann's study, and also stated by this study, is so important that it cannot be voiced often enough or loudly enough. To put it simply, the evidential value of blue cotton can no longer be considered low merely by virtue of the fibre being blue and cotton. Perhaps for that reason alone, this study is very welcome.

To be fair to the authors, the paper does have two additional aims which distinguishes it from Biermann's study, that is the investigation into intra-garment variation of blue cotton garments and whether or not lessons learned from the process can be applied to alter the analysis schedule so as to make the process of examining blue cotton fibres more efficient. It is somewhat disappointing however, that such a small proportion of the study is devoted to the very aims that make the paper distinctive.

In relation to the intra-garment variation the authors quite rightly point out the difficulties in assessing this issue that are inherent with this fibre type and industry practice in general. These factors are widely known amongst the forensic fibre community yet they seem to come as a bit of a surprise to the authors.

In relation to the alternative analysis schedule, the motivation to change procedures for the sake of improving the efficiency of what is a time consuming and tedious process is to be highly commended. However, to those in the industry, the pathway proposed is somewhat odd, and it is not clear where the efficiency gains are likely to come from.

As the paper promotes the use of UV-VIS MSP, and assuming that this level of analysis is intended as the screen, the pathway appears to suggest mounting blue cotton fibres directly onto quartz slides and coverslips performing the analysis, re-mounting those fibres for microscopy, and then extracting the fibres for TLC at the end. The existence of a TLC step at the end is particularly bizarre as MSP is widely accepted as complementary to TLC and one wonders where TLC can add value to a process that is producing 0.99 DP. It's unclear whether this new process is the 'swing' or the 'roundabout' but either way, this proposed alternative pathway appears to offer little comfort.

The Journal of Forensic Sciences (JFS) had two fibre related papers for us this year.

The first paper "Selection of an Adhesive Tape Suitable for Forensic Fiber Sampling" described a laboratory's process for choosing a particular tape for recovering fibres. These types of study are necessary these days, particularly in response to accreditation requirements where laboratory consumables require to be validated prior to use. Tapings are a type of material used to harvest a wide range of evidence types and as such are of interest to Trace Evidence examiners, DNA analysts and others. All of whom have separate requirements for a tape that need to be accommodated somehow. This is not an easy task, as most tapes are not designed specifically with evidence recovery in mind. Each lab will have different requirements and the recommendations found here are unlikely to universally apply, however the criteria used to assess the tapes were sound and the best solution for this lab was found.

The second paper from JFS was entitled: "DNA Analysis of Natural Fiber Rope" and is a good example of the different approaches that academia and caseworking forensic scientists take to research and development. It is disappointing that the requirement of a skilled scientist to perform microscopy is highlighted as a disadvantage....particularly as the DNA department will need a microscopist to find the tiny recovered fibres, screen them and package them up for you. Tell you what, whilst we're there, we might as well identify them as rope fibres and save us all the hassle.

So you want a job in forensic science ....

2008-11-27T12:07:00.002Z

Our recommendation to those wishing to pursue a career in forensic science is to focus on getting a good general education first. We cannot stress this enough. Third level education is very expensive and in this uncertain climate today, you need to ensure that you have plenty of flexibility so that you can appeal to different employers.The best science degrees will give you a better offering in the overall marketplace, particularly if opportunities within forensic science are limited, which is likely to be the case. Don't be swayed by the marketing claims of Universities, no employment in forensic science can be guaranteed by any of them. Be mindful that student numbers are high on their list of priorities, why else would there be such an explosion in forensic science courses? Forensic science sells seats......

A post graduate degree in forensic science may give you an edge in the recruitment market – but that is not guaranteed, and doing post-graduate work in forensic science should be weighed up against getting real life experience in a scientific laboratory setting. A lot of thought should be given to whether or not to pursue a PhD in the hope of securing forensic employment as it is unlikely to secure you a higher level entry than others of lower qualifications.

You need to keep a very close eye on the level of debt you incur during your time as a student, because the likelihood is that entry level positions will not pay well and put your finances under considerable pressures. Employers are paying more attention to candidates personal finances as they must assess the level of risk of candidates leaving owing to financial hardship, caused primarily by debt incurred whilst a student.

Contact Traces view is that we are interested in mature, enthusiastic candidates who have a good general scientific education and who have the potential to become the best forensic scientists in the country. We are likely to have to spend considerable resources training people in the first year so we need to ensure that the fit between employer and candidate is absolutely right from the start.

For all candidates it goes without saying that the most important part of your application is what it says about you, the individual – we only have your piece of paper to judge you – so give us a chance to see who you are; after all you are more than the letters after your name.

Be under no illusion though, it is hard to get a job in forensic science. Each forensic scientist has their tale to tell of self sacrifice and the lengths they have had to go to make their dream of being a forensic scientist come true. It will be no different for you. You can expect to have an enormously rewarding job, but it certainly doesn’t pay as well as you may expect, and the stress and responsibility on individual scientists can be great. It is not for the faint hearted and it’s not like it looks on the telly.

Peer reviewed research

2008-11-19T09:44:00.019Z

The value of peer-reviewed research has been the subject of much debate over many years, and is not a debate unique to forensic science. What makes research in forensic science distinct from other academic research is the potential impact of it. We rely on peer reviewed publications not only as a pool of knowledge to draw from when formulating our opinions, but also as a means of validating our internal processes. For UKAS accredited labs, or those aiming for UKAS accreditation, the 17025 standard states merely that "...the laboratory shall select appropriate methods that have been published either in international, regional, or national standards, or by reputable technical organizations, or in relevant scientific texts or journals..." but no specific mention of peer-review is made. The standard is silent relating to what constitutes a reputable technical organization or a scientific text or journal.

The value of peer-reviewed research has been called into question by the Omagh verdict in relation to its use as a means of validating internal laboratory processes, and the issue of validation of forensic methods is being dealt with by the home office regulator .

Whatever the outcome of the Forensic Regulator's work regarding this issue, the fact remains that operational forensic science laboratories need to publish their work. For the ultimate measure of R&D these days is not in the number of citations, it is in whether or not R&D projects can transfer successfully into day-to-day operations, perhaps even conveying the laboratory with a competitive advantage in the marketplace. Delays in moving R&D work into operations caused by the wait for published approval can be fatal, after all budgets do not stand still in awe of scientific journals.

So, right now, operational forensic science R&D needs a process to get the work published quickly and in a manner that allows some transparent peer-review to take place. Do laboratories need traditional forensic science journals to achieve this? Is there another way to achieve this?

Global Forensic Science Today http://www.globalforensicsciencetoday.net/ appears to be a good start. It's great that you can download the issue at a minimal cost and that the articles are written by experienced operational forensic scientists. It does not appear to be peer-reviewed in the traditional sense, but if a simple, quick, online system could be developed to provide the peer-review, it could be the perfect solution.

Welcome

2008-11-18T10:22:00.012Z

Welcome to our blog. This blog serves to present our views and highlight past, current and ongoing future research into trace evidence and deal with issues affecting caseworkers in trace evidence in the United Kingdom.

We believe that scientific debate is vital to the health of our profession and we reserve the right to comment on any published work or any verbal presentations made at conferences.

This blog is not intended to be an online forum on forensic science and for that reason we do not allow comments to be posted directly through the blog. However, we welcome comments and submissions from fellow colleagues in trace evidence, submittted through our website http://www.contacttraces.com/, which we will consider for publication on a case-by-case basis.