Solving Crime using Novel 3D Imaging Technology

Using Advanced Forensic Imaging Technology to Improve Quality of Evidence in Homicide Investigations to Secure Criminal Convictions.

Forensic science has been the cornerstone of the justice system since fingerprinting was first introduced in criminal investigations in the 19th century.

Today, novel image processing methods and 3D visualisation techniques developed by Professor Mark Williams and colleagues at Warwick Manufacturing Group (WMG) have provided police investigators with a powerful new tool for uncovering and evidencing crime. The involvement of non-invasive scanning technology adds significant value to forensic analysis at the front end of investigations before complementary destructive processes are deployed. These techniques have not only enabled police forces to solve complex crimes, but also assisted the Crown Prosecution Service (CPS) in their evidence reviews and presentation of cases.

Warwick’s research is making a positive contribution to the UK’s criminal justice system, ensuring victims of crime and their families receive the justice they deserve.

The challenge

Computerised Tomography (CT) is an X-ray technique where many scans are digitally combined to provide an accurate image of a solid cross-section of matter. The most well-known application of CT is in medical CAT scans (Computerized Axial Tomography), where axial rotation around a person produces a 3D image of their skeleton.

Micro-CT relies on the same underlying technology but is many times more detailed, down to a thousandth of a millimetre (micron) scale.

Still, optimisation methods are necessary to reduce scanning time and minimise image artefacts which obscure important detail at higher resolutions. Resolutions at this level provide a non-destructive technique to characterise materials by probing and measuring the structure and properties of objects and organs.

Our approach

The research has focused on two key areas:

• Novel image processing technique development

• 3D model reconstruction algorithms to produce manageable data sets for 3D visualisation in micro-CT.

Collaborating with University Hospitals Coventry and Warwickshire NHS Trust, Professor Williams and colleagues created methods and unique algorithms for reconstruction, in parallel with human anatomy studies. They then produced models of anatomical features, including the heart, hip and femur. The aim of the anatomical research was to validate novel surgical procedures.

This was done physically - by using human cadavers, and virtually - through high-resolution scanning and reconstruction. This enabled Warwick and West Midlands Police to develop controlled baseline datasets of normal anatomical variation and common types of injuries, which are then used to support Home Office Pathologists in helping determine cause of death.

Our impact

Between 2014 and 2020, micro-CT was used by 18 police forces in investigating 171 criminal cases.

Of note, in 2014 Professor Williams and colleagues applied their novel 3D technologies including micro-CT and 3D printing to the forensic investigation of a suitcase found in a canal in West Midlands, containing a dismembered human body. High-resolution 3D prints of burnt human bone provided a crucial link between the site where the body had been disposed of and the home of the murder suspect – leading in part to a murder conviction.

In another case, following the death of an 18-month-old girl, micro-CT scanning was conducted at WMG and showed multiple injuries on the ribcage and thigh bone, indicating healing processes that had begun at different stages without proper medical care. The Crown Prosecution Service stated this finding was instrumental in establishing the circumstances and cause of injury and death of the infant.

To accelerate and facilitate wider uptake of this technology, the Forensic Centre for Digital Scanning and 3D Printing, a partnership between West Midlands Police and Warwick, was established in 2019. Through the Centre, over GBP500,00 in process savings have been achieved with more than 140 specialist practitioners receiving continuous professional development training on image processing methods and 3D visualisation techniques.

Thanks to Professor Williams and colleagues, Warwick research will be playing an active role in the criminal justice system for years to come.

Watch how technology at Warwick is supporting West Midlands Police in collecting evidence for investigations