Forensic Science is any science used for the purposes of the law, and therefore provides impartial scientific evidence for use in a court in a criminal or civil investigation and trial. Forensic Science is a multidisciplinary subject, drawing principally from chemistry and biology, but also physics, geology, psychology, social science, etc.
In a typical criminal investigation crime scene investigators, will gather material evidence from the crime scene, victim and/or suspect. Forensic scientists will examine these materials to provide scientific evidence to assist in the investigation and court proceedings, and thus work closely with the police. Senior forensic scientists, who usually specialise in one or more of the key forensic disciplines, may be required to attend crime scenes or give evidence in court as impartial expert witnesses.
The evidence examined by forensic scientists can be anything that is likely to inform the legal process and make one outcome more or less likely. As such it may be something biological in origin like blood or other body fluids or hair; it may be something physical like paint or glass or it may be some chemical like drugs or a flammable substance. This follows the principle that 'every contact leaves a trace' that will offer potential evidence to link a suspect with the scene of the crime, the victim or the weapon.
Examples of forensic science include the use of gas chromatography to identify seized drugs, DNA profiling to help identify a murder suspect from a bloodstain found at the crime scene, and laser Raman spectroscopy to identify microscopic paint fragments.
Activities carried out by a forensic scientist may include:
- Recording findings and collecting trace evidence from scenes of crime or accident.
- Analysing samples such as hair, body fluids, glass, paint and drugs in the laboratory.
- Applying various techniques as appropriate; e.g. DNA profiling, mass spectrometry, chromatography.
- Giving evidence in court
In contrast with popular perception, this is a highly scientific role, which often involves detailed, painstaking work. Job activities very much depend on the area of forensics in which you work. The main areas are:
- Chemistry: which is connected to crimes against property, such as burglary and arson. Work in this area involves the examination of paint, chemicals, etc., including fire investigation and accident reconstruction;
- Biology: which is connected to crimes against people, such as murder, assault and rape. Work in this section involves DNA testing and the examination of minute contact traces, such as blood, hair, clothing fibres, etc.;
- Drugs and toxicology: Work in this section involves testing for restricted drugs, examining tissue specimens for poison detection, and the analysis of blood and urine samples for alcohol, for example in drink driving offences.