the forensic institute

Student Projects: The Forensic Institute Research Network (FIRN)

Chemical processes at fingerprint-metal interfaces

Fingerprints have been an extremely important type of evidence in criminal investigations, and the identification of criminals for well over 100 years. Even with recent advances in DNA evidence, fingerprints remain a primary method of identification in crimes ranging from domestic burglary to murder and rape. However, the collection of fingerprint evidence from scenes of gun crime has remained an area of difficulty until very recently, with advances in the imaging of fingerprints on spent brass cartridge cases.

It is known that human sweat as deposited in fingerprints is able to corrode metals including brass. This research examines the chemical reactions that may occur between a human fingerprint and brass, further to understand the science behind this recent advance in imaging fingerprint corrosion. We will examine the correlation, if any, between the ions in the fingerprint residue and the degree of corrosion on brass. We will also describe the differences in corrosion between brasses of varying compositions. A range of techniques have been used in this research including ICP-MS, SEM-EDX and electrical potential difference measurements.

Andrew Meekins & Dr. PENNY CHALONER

University of Sussex & Northamptonshire Police

ajm49@sussex.ac.uk & penny.chaloner@sussex.ac.uk

Oral presentations

Cognitive style, processing sets and face recall >>

The Scanning Kelvin Probe (SKP) for the visualisation of fingerprints on metal surfaces >>

Investigation into the user of parallel processing techniques to speed up file carving using Graphical Processing Units (GPUs) >>

Assessment of the validity of using pigs as a model for humans in forensic entomology studies >>

Chemical processes at fingerprint-metal interfaces >>

Determination of visual thresholds of image usefulness in fingerprint compression >>

The use of ion beams for forensic analysis >>

General purpose graphics processing units in security >>

An investigation into the use of dehydration as a method of preserving dna in biological forensic samples >>

Real world detection of cocaine at the picogram level in an urban environment >>