CSI: DUNDEE

Project Description

Forensic science is a far reaching subject area which touches upon many scientific disciplines including chemistry, biology and physics whilst also interacting intimately with the world of law, ethics and civil liberties. It is a field which is largely constituted by superficial analytical techniques that are based around visual observation and expert interpretation. Despite the significant scientific advances of recent times, there is a surprising lack of robust and putative scientific testing used in forensic science. Although regarded as the holy grail of forensic evidence, even DNA traces can be argued against in a court of law given the chance, no matter how slim, that it may belong to another person. This highlights a real need for the development of additional tools that can be used to acquire powerful evidence that can ensure justice is being served appropriately and categorically. Our project aims to tackle this issue, by adopting a science first approach, a tactic which we found to be missing in current forensic methodologies. Our Forensic Toolkit has three key components which we hope will offer new solutions to longstanding challenges within forensic science but also improve efficiency of older methods.

The first of these tools is one which would most likely used in an investigative nature, in the initial stages of an investigation. Distinction between different body fluids at a crime scene currently requires the use of numerous time consuming methods. Our BioSpray aims to provide an efficient, all in one solution that can be used to detect and distinguish between body fluids, namely blood, semen, saliva and nasal mucus, based on fluorescent nanobead technology in combination with synthetic biology. In theory, identification would occur by spraying a solution of nanobeads crosslinked to a mixture of binding proteins, one unique for each fluid, onto a sample, allowing for efficient visualisation and immediate identification.

One of the most enduring challenges faced by forensic scientists is the ability to determine the age of fingermarks left at crime scenes; something that currently cannot be done. This is due to the extensive range of factors which affect fingermark composition. Through the use of principle component analysis (PCA) on a set of fingermark composition data, we hope to identify a potential set of kinetically related compounds within fingermarks that degrade at a constant rate in time. This could then be modelled into differential equations. After the most reactive composites have been identified using PCA, a synthetic biology tool can be used to target them for age deduction.

Crime cases which involve marks being left on bones, including sharp as well as blunt force trauma, are currently examined mainly by visual methods such as microscopy. Although these techniques provide powerful evidence, there is no chemical test currently in place which is used to detect residue deposited on bone by implements used during a crime. Such information may prove incredibly useful in establishing whether it is worth pursuing further tests, which tend to be very costly, by identifying if there are any particles on the evidence in the first instance. Since chromium is a key component of stainless steel, from which many common weapons and tools are made, our aim is to design a sensor that could determine the presence of chromate on bones.

Team:Dundee/description

Project Description