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Centre for the Forensic Sciences Blog



CFS Seminar Series – Julie Allard PFS

By uctzgam, 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 Seminar Series – Brian Rankin

By uctzsmi, on 23 January 2014

CFS Seminar lead by Brian Rankin (Head of the Centre for Forensic Investigation, Teesside University)
January 22, 2014

In addition to most of the other seminars that focus on specific forensic studies, this seminar was aimed at highlighting the market issues around forensic science. If you were not aware of the importance of this as a forensic science student or researcher, you would have been afterwards. Brian Rankin pointed out the main challenges, which were then discussed among the group. This forced you to think about the implications of these issues for the future of forensic science and yourself herein. I found it very enlightening to discuss these issues with someone that has experience in both the academic and policing environment, and who is very passionate and enthusiastic about his, and our, field.

For example, I think many forensic science students do not realise the importance of effective case management to save time and costs in the CJS, which is said to be improved by using streamlined forensic reporting. What also I found noteworthy and worrying are the different requirements for the laboratories in the police forces and the independent forensic companies to be accredited. To me, this also implies that the shutdown of the Forensic Science Service (FSS) resulted in many problems regarding quality assurance and maintaining the code of practice. Luckily, with the help of the Forensic Science Regulator, such issues are currently being addressed. Also, with the shutdown of the FSS, universities in the UK now bear the responsibility of research and development, which I believe should be done with close communication and participation of the government, police and commercial companies to guide forensic research to address current issues.

Examples were given, such as the investigative process of the murder on Jill Dando and the arrest of Shirly McKie which put some of the current issues into perspective. These are just two of many more examples that show the significant impact of the improper handling of forensic evidence. This seminar once again highlighted the importance of multidisciplinary and collaborative research in the forensic domain which was both eye-opening and encouraging. Lastly, even though job opportunities in this field are limited, it was highlighted that forensic science students are equipped with many skills that can be applied in a lot of other problem-solving environments.

CFS Seminar Series – Professor Bjorn Reif

By uceeanc, on 18 January 2014

Professor Reif from the Norwegian Defence Establishment (FFI) gave an exciting talk on the use of computer models in understanding the distribution of explosive residue after an explosion had occured. The fundamental physics governing the movement of particles in air was outlined and a description of the computational fluid dynamics methods used to model the phenomenon was provided. Models produced at the FFI of the Oslo bombings were presented to demonstrate the accuracy of the method and the usefulness of combining computational skills with experimental data. The importance of understanding the dispersal and deposition of particulate explosive residues following detonation would not only be useful for forensic scientists looking to efficiently process a post-explosion crime scene and sample for such traces, but would also benefit subsequent environmental clean up procedures – in particular where ‘dirty’ bombs may have be used.

– Nadia Abdul-Karim