New academic year approaching

By Kirstie Hampson, on 24 September 2015

Next week we will welcome our new cohort of 20+ MSc Crime and Forensic Science students to UCL. Our previous cohort recently submitted their dissertations and are already off working, continuing their studies or having a well-earned break! We have some exciting extra-curricular events planned for the next two terms with lots of seminars plus a public event Forensic Science: “The Good…The Bad…The Ugly?” taking place on 8th October. We hope they will enjoy the next 12 months and take advantage of all the opportunities that UCL and the Centre for the Forensic Sciences have to offer.

Forensic outreach with Inspire!

By Michaela Regan, on 19 August 2015

In May and June, Sherry, Sally, Nadine and I had the opportunity to provide three forensic outreach sessions to 3-5 year olds at three different schools in Hackney. All of us have had different experiences with outreach but none of us have worked with such a young age group, and we were aware that factors such as their attention spans and their vocabularies would affect how we delivered the sessions. We knew that we needed to make it simple but fun so that the children would stay interested, which is challenging when you are used to explaining your research to a more academic audience.

iDiscover EYFS - UV light on hands

UV light on hands

To start off, we briefly explained the process of investigating a crime (demonstrating the role of witnesses and searching for ‘clues’ to ‘catch the bad guy’) through different activities. We demonstrated the difficulty of being a witness by giving them an image to memorise for a minute and then asking what colours the different objects were. After which, we got them to try and link paw prints to different animals as a way of describing the theory behind footprints. To conclude, we wanted to find a memorable activity to inspire them so we used fluorescent powder to demonstrate the way trace evidence can transfer and persist; putting fluorescent powders on our hands and then shaking theirs. After we shook all their hands we turned off the lights and used a blue light to show them that even though evidence may be invisible to the naked eye, sometimes it can still be located. I feel these activities were very successful with the children and that they were very enthusiastic and sometimes even amazed by them. I also found it thoroughly enjoyable and motivational – it was encouraging to see them so interested in forensic science and I hope that this encourages them to keep learning more about this subject area.

CFS research away day

By Kirstie Hampson, on 30 July 2015

Our researchers (academics and PhD students) have all spent today in Oxford on an away day focusing on research and collaboration. Among the activities will be a scavenger hunt around Oxford, so teamwork will be critical! We will blog about the day in a couple of weeks, and we are of course hoping that it will result in lots of fruitful research collaboration, so watch this space.

9th International Crime Science Conference

By Kirstie Hampson, on 16 July 2015

We ran a session at the conference today with talks from Professor David Spiegelhalter (University of Cambridge) and Dr Gill Tully (Forensic Science Regulator). It was well attended and both speakers gave thought-provoking talks on how forensic scientists communicate their findings in court, and how we express uncertainty within legal (and other) contexts. Both were of the opinion that juries should be given probabilities in the form of statements, but that these statements should be standardised and as transparent as possible. Professor Spiegelhalter stressed the importance of expert witnesses being able to not only interpret statistical probabilities (i.e. likelihood ratios) but also be able to communicate them clearly. It was a fascinating session and seemed to generate a lot of discussion among the delegates present.

Summer at the CFS

By Kirstie Hampson, on 2 July 2015

The last two terms have flown by in a flurry of teaching, examinations (marking!), and research, and our MSc students are now busy working on their own research projects. We are very busy planning events and preparing to relaunch our website for September 2015. Here are a few of the conferences and other events we have coming up:

The 9th International Crime Science Conference at the British Library, London on 16th July 2015

SPARK Festival London (UCL Engineering) at the Queen Elizabeth Olympic Park, London on 30th and 31st August 2015

The 7th European Academy of Forensic Sciences Conference in Prague, Czech Republic from 6th to 11th September 2015

We are also looking forward to welcoming our new cohort of MSc Crime & Forensic Science students in September 2015, and will be preparing for their arrival over the next couple of months.

Forensic Geoscience: Future Horizons

By Kirstie Hampson, on 9 December 2014

The London Geological Society’s conference on Forensic Geoscience: Future Horizons took place on Wednesday 3rd December.  It attracted over 100 international delegates with interests in the forensic applications of the geosciences.  UCL graduate students Kirstie Scott, Beth Wilks, Kelly Cheshire and Nadine Smit presented their research at the meeting.  There was a full programme of presentations covering primary research results and casework examples that spanned a wide range of sub-disciplines within forensic geoscience.

For full abstracts please see the website.

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Fingerprinting – where chemistry and forensic science can come together

By William Peveler, on 26 May 2014

Researchers at Hanyang University in Seoul have recently published work in Nature Communications describing a new polymeric material they have developed, which is capable of mapping sweat pores in the human fingerprint at high resolution (doi). The polymer changes colour and becomes fluorescent when exposed to moisture (hydrochromic), even at low concentrations, and thus when a finger mark is deposited on a sample of the material, a point pattern fluorescent image is generated which can be recorded with fluorescent microscopy. The researchers go on to compare a selection of these to ninhydrin-stained latent marks, also exhibiting pore structure, to show a good match. They argue in their paper that the analysis of sweat pores in marks, rather than the typically used ridge structures, means that an incomplete or indistinct mark can still be used to generate a match if sweat pores are available. They neglect to discuss, however, the availability of sweat pore location information in lifted marks; and all their analysed marks were deposited directly onto the polymer itself or digitally scanned, rather than a more realistic examination of real world marks against their material as a reference.

It is exciting to see work with a strong forensic component featuring in such a high impact publication, beyond the normal forensic science journals, and this is partly due to the high quality chemistry content regarding the design and synthesis of their new polymeric material, and an in depth analysis of its hydrochromic properties. There is a good chance that this work will be widely covered in the popular-science and lay media too, due to the all-important CSI effect (e.g. here). However, are the results reported actually important forensically – or are they merely a handle to boost a good supramolecular chemistry paper to being a superstar nature paper? As the Korean authors admit, the materials they describe are not entirely novel; this class of polymers was first posited for mark development by an Australian group led by Tahtouh in 2011 (doi). However this initial research was published in Forensic Science International, where no doubt it escaped the notice of much of the chemical sciences and of the wider establishment, despite its forensic rigour in investigating the application of these polymers as mark developers on a variety of surfaces.

So maybe there are two messages that can be taken from this paper. Firstly, the mapping of sweat pores within finger marks may be an important part of dactyloscopy in the future, with the advent of new materials such as these allowing easy collection of sweat pore information.

However, a second message to take away might be that; if, as a forensic scientist you’ve stumbled across what you feel might be the next big thing, maybe get together with a chemist/physicist/etc. and big up the background science, and offer it to a journal beyond the forensic sphere. For example FSI has an impact factor of ~2.3 whereas Angewandte Chemie Int. Ed. scores ~13.7, and as evidenced by a recent spate of fingerprinting related papers they have published, the latter loves a good forensic science article. The chemists carrying out this fundamental research into novel development agents and materials often do not understand the intricacies and limitations of day-to-day practitioner case work, and the forensic scientists working on minor improvements to their well honed but basic techniques often do not look at the high-level theoretical work going on to further their ideas –it’s time to get the two together and then maybe there could be a lot more Nature papers on forensic science.

Many thanks to Helen Earwaker for informative discussion. Lee et al. 2014 “Hydrochromic conjugated polymers for human sweat pore mapping”. Nature Comms, 5, 3736 – is available as an open access paper from dx.doi.org/10.1038/ncomms4736.

CFS Seminar Series – Dave Baldwin PFS

By Michaela Regan, on 11 March 2014

March 6, 2014

This week’s seminar was a brief introduction to the use of tool mark comparisons in criminal investigations. It was given by Dave Baldwin who has experience working for the Forensic Science Service (FSS) and for Principal Forensic Services.

The seminar provided us with a brief background into the different types of tool mark impressions such as impressed marks (when a contact forces them together without movement) or dynamic marks (striations). These unique impressions allow an examiner to determine the action that caused the formation of such an imprint e.g. what type of instrument caused the forced entry to a door, the breaking open of a window, cut the fence or chain. Additionally, these marks can be left on the ribs or on the skull of a victim which allows the examiner to associate a suspect to a knife or weapon.

The complicated part is that it is important to understand the information surrounding the case as he needs to know what questions need to be answered in order to determine the right course of analysis. For example, are we trying to associate a suspect to a weapon or deduce whether that particular object caused the impression at the scene? Are we trying to determine the type of instrument that would have caused this impression like a screwdriver, and is it possible to determine that a specific object at a scene caused the impression?

The examiner will look at a variety of features to answer these questions such as:
– Class features: measurable features of a specimen which indicate a restricted group source
– Sub-class features: discernible surface features of an object which are more restrictive than class characteristics
– Individual characteristics: marks produced by the random imperfections or irregularities of tool surfaces. These random imperfections or irregularities are produced incidental to manufacture and/or caused by use, corrosion, or damage. They are unique to that tool and distinguish it from all other tools.
– Manufacturing processes: involves the transfer of rapidly changing or random marks on to work pieces caused by tool wear and chip formation or by electrical/chemical erosion. Microscopic marks on tools may then continue to change from further wear or abuse. These irregularities are considered unique and capable of being used to individualize or distinguish one tool from another.
– Finishing processes: sanding of lands resulting in unique land impressions to make it look attractive.

To analyse these features, examiners use a variety of instruments such as bench and comparison microscopes, casting techniques and a new instrument that is occasionally used is a comparison SEM (scanning electron microscope). This allows them to compare and contrast their analysis, but since these are compared they are at risk to a degree of subjectivity. Therefore, it is important to remain as objective as possible by following a rigid scientific methodology as bias is becoming an increasing issue within forensics analysis.

Finally, this introduction gave a small insight to the duty of a forensic tool mark examiner and the critical eye one needs to have to perform such work. Further, it showed the ease with which bias can cause the occurrence of inaccuracies in the analysis stage showing that great care needs to be taken when dealing with any type of evidence.

CFS Seminar Series – Julie Allard PFS

By Sally Gamble, on 27 February 2014

February 6, 2014

This seminar was from one of Principal Forensic Services’ forensic biologists, Julie Allard, who specialises in body fluids and their potential to provide DNA profiles for use in a criminal investigation. The types of body fluids discussed included blood, semen and saliva, all of which have presumptive tests for their detection:

  • Blood – Leucomalachite Green (LMG) test
  • Semen – Acid phosphatase test
  • Saliva – Phadebas test

These tests produce a colour change indicating the presence of the body fluid in question, and can be used on different materials including clothes and weapons. Once areas presumed to contain these body fluids have been identified, samples can be sent for DNA profiling. This is where it starts to get a bit tricky, not only can different levels of interpretation be addressed in relation to the DNA evidence obtained, the DNA evidence itself can be troublesome! For example, is there enough DNA present to produce a profile? Is there a mixture of two or more people’s DNA present? Has the DNA profile come from the body fluid in question? Whose DNA and therefore body fluid is present in the sample? Can the presence of a given person’s DNA determine the actions of that individual?

Julie emphasised the importance to take the context of the case into account when answering these questions. A forensic scientist may address the activity level of the evidence, e.g. Person A kicked Person B but must not address the question of whether or not a person committed a crime or not, since this is the job of the jury. The CAI (case assessment and interpretation) model aids a forensic scientist in evaluating the evidence they are given in a balanced, logical, robust and transparent manner.

However, the interpretation of evidence for use in court is a contentious subject, Julie pointed out that as new information arises concerning a case, the evidence must be re-evaluated in light of this new information. Furthermore, it is likely that the information that the prosecution scientist has received does not correlate with the information received by the defence scientist, leading to much disagreement between experts!

Finally, for forensic scientists to effectively use the CAI model to clearly show how a given conclusion was derived from the evidence provided, in light of the case information, Julie stressed that the logical assessment and interpretation steps need to be based upon empirical data that mimics the forensic context.


CFS Team at AAFS

By Aysha Chaudhary, on 18 February 2014

The annual meeting of the American Academy of Forensic Sciences is currently underway in Seattle. Dr Morgan will be in attendance, accompanied by a group of CFS doctoral students who will be presenting their research.

Helen Earwaker will be presenting her poster titled “Fingermark Submission Decision Making Within a United Kingdom Fingerprint Laboratory: Do Experts Get What They Need?”
Criminalistics Poster Session [Wednesday]

Georgia McCulloch’s presentation is entitled “Is High Performance Liquid Chromatography (HPLC) a Useful Addition to Current Geo-Forensic Analytical Techniques?”
Criminalistics Session II [Thursday 1:30pm]

Michaela Regan will be presenting her poster, titled “A Study to Determine the Use of Gunshot Residue Upon Clothing as an Item of Evidence”
General Poster Session [Wednesday]

Sherry Nakhaeizadeh will be giving a presentation on “Cognitive Bias in Forensic Anthropology: Visual Assessments of Skeletal Remains Are Susceptible to Confirmation Bias”
Physical Anthropology [Friday 12:00pm]

Dagmar Heinrich’s presentation is entitled “A “Realistic” Study of Sharp Force Trauma Recognition in Burned Remains: The Forensic Implications”
Physical Anthropology [Saturday 12:15]