The BAHID Autumn Conference Workshops

Individualised and non-contact postmortem interval estimation: combining thermal 3D imaging and numerical thermodynamics

Leah S. Wilk (Host), Gerda J. Edelman, Martin Roos, Roelof-Jan Oostra, Maurice C. G. Aalders

The postmortem interval (PMI) plays a key role in forensic investigations, as it aids in the reconstruction of the timeline of events.  Currently, this information is provided by an empirical model (Henssge’s nomogram) describing postmortem body cooling. However, this model is subject to three significant limitations. First, the underlying experiments were conducted under standardized conditions, restricting applicability of the model to a specific subset of forensic cases. Second, in order to broaden this suitable subset, qualitative correction factors were introduced, rendering this approach subjective. Third, use of this model requires an invasive measurement of the victim’s core (rectal) temperature, risking contamination and destruction of other traces. Consequently, there is an urgent need to develop a non-subjective, widely applicable, and preferably non-invasive method for PMI estimation. To address this need, we developed a thermodynamic finite-difference algorithm, providing a rigorous method to simulate postmortem body temperatures. By combining this algorithm with 3D imaging and skin thermometry, we achieve accurate and non-invasive PMI estimation for bodies of arbitrary shape and posture. Moreover, using thermal imaging, this approach even allows non-contact PMI estimation. Finally, we extended the method’s applicability to cases where thermodynamic input parameters (e.g., ambient temperature) are unknown, by combining it with surrogate-model-based parameter optimization. Crucially, we validated this approach on deceased human bodies (both in the lab and at real crime scenes), and achieved the lowest PMI estimation errors to date (0.18h ±0.77h).

The learning outcomes of this workshop are two-fold: participants will be (i) introduced to the theoretical foundations of thermometric post-mortem interval estimation and (ii) will learn how to perform 3D imaging (using a mobile device) and non-invasive skin thermometry (using small sensors) to generate data which can be used in conjunction with thermometric modelling software to non-subjectively estimate the post-mortem interval directly at the crime scene.

BOOK EARLY - this workshop will run twice during the afternoon.  

 

Exploring Personal Effects in Forensic Identification

Dr Maria Maclennan, Dr Jan Bikker, Prof. Pavlos Pavlidis and Harry Lawson

Personal belongings such as jewellery, watches, glasses, and photographs are often recovered with the deceased, including people on the move – personal treasures or protective talisman for the journey ahead. Whilst not sufficient on their own in identifying the deceased, these ‘secondary’ methods can serve to support identification via ‘primary’ means (such as DNA, fingerprinting, or dental records). The unique or sentimental nature of many items means they may also be recognised by families, representing the last tangible link to a missing loved one.However, the limitations of personal effects in the identification process must also be considered, with many objects interchangeable between persons - gifted, stolen, or traded.

Informed by the ongoing collaborative and multi-disciplinary research conducted by the project team; this multi-faced workshop encompasses a short presentation, film viewing, practical workshop, and discussion session. Attributed to the identities of more than 100 identified and unidentified migrants; participants will hear stories of the personal belongings which currently reside in the Mortuary of the University Hospital of Alexandroupolis, Greece. They will have the opportunity to approach, identify, and describe their own objects, and learn how to establish a range of investigative clues as to an individual’s identity. They will also have the opportunity to contribute to future practice and guidance around the forensic use of personal effects in the migration context in Greece.

Participants are encouraged to bring along a personal object of their choice to the workshop.

 

Agilent Resolve unit Raman spectroscopy use in Chemical, Biological, Radiological and Nuclear (CBRN) and covert policing.

Jim Smith, CSM Derbyshire Police

EMSOU’s remit is to tackle the most serious, organised and violent crime countering terrorism, extremism and providing forensic services on behalf of the region. We are a collaboration of 5 east midland forces covering an area of 5.2 million people. Its our job to identify, disrupt and prosecute those individuals or groups causing the most harm to our communities. This piece of equipment is used frequently within the region to identify substances and resolve incidents quickly and safely. It has a wide range of uses and its database covers a vast array of chemicals used for the manufacture of illicit drugs and explosives.

Participants are encouraged to bring a small powder sample (unlabelled and obviously not dangerous or illegal) with them to the workshop. 

This shorter workshop is limited to 6 participants per 30 minute session, with several sessions running throughout the afternoon. If selecting this session, we will let you know which slot you have been booked into.