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CFS Seminar Series – Giorgio Blom (Staffordshire University)

MichaelaRegan15 March 2016

Last Thursday, we had the pleasure of welcoming Mr. Giorgio Blom to our CFS seminar series. He gave us a fascinating talk on his PhD project which is looking at the use of analytical techniques for the discrimination of decomposition products (e.g. putrescine, cadaverine, and methylamine) originating from a buried corpse. Giorgio has been looking at using these different techniques to narrow down the search area when looking for missing people.

Giorgio introducing his topic

Giorgio introducing his topic

Currently, the police use victim recovery dogs or geophysical instruments such as ground penetrating radar to locate possible clandestine graves. The problem is that when you have a large surface area, it’s very difficult to thoroughly search the whole area using these techniques. This is where Giorgio’s research comes into effect.

During his project, he focused on the following instruments to detect these decomposition products:

  • GC-MS (gas chromatography-mass spectrometry);
  • Ion chromatography;
  • HPLC (high-performance liquid chromatography);
  • LC-MS (liquid chromatography-mass spectrometry).
  • Even though these instruments are still in the research stage, they’re showing great potential for the detection of decomposition products. Before finishing his talk, he gave two examples of locations where he tested these instruments: in both an aquatic and terrestrial environment, in order to determine their suitability for casework. Overall, his research was very impressive and I really enjoyed his talk!

     

    CFS Seminar Series – Hamish de Bretton-Gordon

    SimonaGherghel15 March 2016

    March 3, 2016

    This seminar was given by former Army officer, Mr. Hamish de Bretton-Gordon. Hamish is currently a chemical weapons expert to NGOs working in Syria and Iraq. His seminar topic was the use of chemical weapons by ISIL and Assad.

    Since the Syrian conflict started, Hamish has been deployed to the conflict area a number of times, where on behalf of OPCW (Organisation for the Prohibition of Chemical Weapon) he has helped set up a CBRNE task force. Additionally, he helps run 32 hospitals and clinics across Syria, where he has trained doctors how to treat chlorine casualties and how to collect evidence that can be further used in a court of justice. His efforts in Syria also include training civilians how to protect themselves against chemical weapons.

    Hamish de Bretton-Gordon in the middle of his presentation

    Hamish de Bretton-Gordon in the middle of his presentation

     

    Hamish shared his experience on sampling and analysis of chemical warfare agents in Syria. He explained that sampling in war zones can be a challenging task due to various factors such as a violent environment, limited amount of time that can be spent on the scene, uncontrolled scene and limited equipment available.

    Finally, Hamish covered different chemical weapons that he has encountered in the Syrian conflict zone, such as chlorine and sulfur mustard. Chlorine, a “choking agent” that has been used for the first time on a large scale in WW1, has been used in Syria in a series of attacks in April 2014. Sulfur mustard, a “blistering” agent, has been used in eight attacks on Kurdish forces from Northern Iraq just in the last two weeks of February 2016, causing more than 200 casualties.

    CFS Seminar Series – Mike Ferguson (CAST)

    MarkAmaral29 February 2016

    Last Thursday we were grateful to be able to welcome Mike Ferguson from The Centre for Applied Science and Technology (CAST), a core part of the Home Office, to come and talk to us. Over a captivating hour, Mike shared with us his case experience and the uses of different search equipment for:

  • counter-terrorism;
  • ground recovery;
  • and marine recovery.
  • 12789935_10153326687325825_1912565782_o

    Mike Ferguson explaining the marine diver hand held sonar.

    He also brought along a variety of search equipment including: ground penetrating radar, a marine diver hand held sonar and a drone.

    IMG-20160229-WA0000

    Drone used for surveying.

    Mike demonstrated some of this equipment and explained how it is used and the information you can obtain. This provided students with an insight on how search and recovery equipment is utilised in the field to aid in investigations. He finished his presentation with a talk about the different subdivisions of CAST and the research being conducted if any students were interested in getting involved with the work the Home Office does. Following the discussion, the students then had a chance to try out some of the equipment for themselves over drinks and snacks.

    CFS Seminar Series – Dave Baldwin PFS

    MichaelaRegan11 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.