Forensic science cover four main categories, pathology, biology, toxicology and chemistry.
Our pathology section conducts post-mortem examinations when they are authorised by the State Coroner.
Forensic pathologists conduct autopsies, or post-mortem examinations to determine the cause of death. Find out more about the coronial process from the Courts Administration Authority of SA website.
We coordinate the imaging of deceased and analysis of specimens collected from the post-mortem. This includes:
- samples of blood, urine, liver, stomach contents and vitreous fluid to test for drugs or poisons
- tissue samples to identify disease
trace evidence - e.g. DNA, unexplained hair or fibres collected from the body to help confirm the circumstances of death, identify persons of interest or reveal their connection to the deceased.
We examine tissue samples taken at post-mortem that have been prepared for microscopy.
We examine bones and other material for information on sex, age, height and race if people cannot be identified through traditional means like visual identification, fingerprints, dental records or DNA.
Learn more about pathology by watching Follow your interest in forensics: pathology (video).
Our biology section detects and identifies biological material on items collected from a crime scene - e.g. clothing, weapons or personal items.
Evidence from a crime can link a suspect or victim to a crime scene or another person. Evidence recovery technicians swab evidence to obtain DNA profiles.
DNA is a complex chemical that is present in most cells. DNA profiles provide information that can help distinguish between individuals, match people to crime scene samples or reveal the identity of a deceased person.
Swabs are usually processed using robotics. DNA is removed from the cell, quantified and small amounts of DNA amplified using a method called polymerase chain reaction (PCR).
Police can request a comparison of a suspect's DNA sample with crime scene samples.
DNA profiles can be uploaded to a local and national DNA database and searched against other DNA profiles. Matches in the database can provide investigative leads for police. Many suspects are identified in this way.
Biological and physical evidence collected from crime scenes or persons of interest is recovered and examined. This includes traces of blood, saliva and other body fluids for DNA profiling. Other forms of evidence may include drug residues or glass fragments.
Evidence examiners also analyse and interpret bloodstains on clothing and weapons. They interpret damage to textiles, such as clothing, to determine if the damage was:
- cut or torn
- if a particular weapon was used.
Learn more about biology by watching Follow your interest in forensics: biology (video).
Our toxicology section analyses blood and tissue samples for:
- unexplained deaths
- driving offences
- criminal offences committed under the influence of alcohol or drugs.
Samples collected at autopsy including blood, urine, liver tissue and stomach content can be submitted to the toxicology laboratory for comprehensive drug screening.
The cause of death may not have been determined at autopsy or it may be important to demonstrate the person’s state of mind just prior to death - e.g. was the person under the influence of drugs or taking their medication?
This service analyses biological samples (blood, urine and saliva) taken from living people:
- Criminal toxicology - refers to the serious crimes of homicide, assault and sexual assault.
Drugs in driving - a drug testing service undertaken for the police and the Minister for Transport and Infrastructure.
Learn more about toxicology by watching Follow your interest in forensics: toxicology (video).
The chemistry section comprises of three separate forensic disciplines that provide analytical services: illicit drugs, trace evidence and document examination.
We analyse suspected illicit drug items to confirm the presence of an illicit compound as well as determining how much of the drug is present. We also examine and provide expert opinion on cannabis crops as well as having chemists’ attending clandestine drug laboratory crime scenes to provide chemical safety advice to police and categorise and sample chemicals and residues for further laboratory analysis.
We also report on illicit drug trends, and issue alerts when detected illicit drugs pose an increased acute health risk.
We examine and compare or identify non-biological trace evidence from a crime scene, a vehicle collision, a suspect or a victim.
Glass analysis - compares the physical and optical properties (and sometimes the elemental composition) of known and questioned glass.
Paint - colour, texture, layer structure, organic composition, ultra-violet (UV) properties and inorganic composition.
Gunshot residue (GSR) - a scanning electron microscope, coupled with X-ray detection (SEM-EDX) and an automated particle search facility are used to identify the form and composition of GSR particles.
Ignitable liquid residues (ILR) - identifies volatile chemicals, often in fire debris, to determine if an accelerant was used to start a fire.
Explosives - identify pre or post-blast residues or substances.
Fibres - compares the physical and chemical properties of known and questions fibres from fabrics, carpets, ropes etc.
Miscellaneous chemicals - physical or chemical analysis of unknown materials to identify or compare them. This can include personal defence sprays, lubricants, metals and vehicle light filament examinations.
We examine handwriting and signatures from questioned and known sources to determine if they were written by the same person. This includes if a document has been altered by examining the properties of the ink, any erasures, additions, obliterated entries or page substitutions.
Learn more about chemistry by watching Follow your interest in forensics: chemistry (video).