From solving murders to dismantling organised crime groups, criminal investigators play a critical role in Australia's criminal justice system as much as they do in private investigations.
In this blog our criminal lawyers Sydney team cover the key responsibilities of criminal investigators in Australia, including how they respond to major crime scenes, gather and analyse forensic evidence, conduct interviews, use surveillance and intelligence to develop leads in order to build a brief of evidence to support prosecution.
The Differences Between a Detective and Criminal Investigator
In Australia, criminal investigations are largely undertaken by a 'detective' which is a police officer who has specialised knowledge and experience in the investigation of serious and complex crimes. A criminal investigator can extend to non-detectives who are trained in criminal investigations.
Unlike general duties police officers, detectives typically operate in plain clothes, focus on reactive investigations, and are attached to Criminal Investigation Units (CIUs), specialist squads (such as homicide, drugs, or sexual offences), or taskforces targeting particular criminal networks or patterns. Their core function is to gather evidence to identify offenders, build prosecution cases and support the criminal justice process from the investigative phase through to trial.
In contrast, private investigators include detectives and extend to non-detective private investigators who can be hired for criminal or non-criminal investigations.
How to Become a Criminal Investigator
A criminal investigator can also be referred to as a detective. They are investigators with expertise in law enforcement concerning criminal law investigations from ascertaining and verifying evidence to gathering evidence through various methods including interviewing suspects. Following their investigation, a criminal investigator will produce a report disclosing the fruits of their investigation impartially. Criminal investigators may also be required to give evidence in court under oath in criminal trials, usually as expert evidence.
It is therefore crucial that in order to become a criminal investigator, one must complete a degree and gain insightful experience in law enforcement. The investigation will be as good as the level of qualified experience of the criminal investigator. There are a various ways to achieve this in Australia.
One such path to becoming a criminal investigator or detective is by completing a Bachelor of Policing (Investigations) or an advance diploma of police investigations in order to then pursue a career as a detective in criminal investigations.
In New South Wales, a police officer becomes a detective by completing the Detective Training Program, a two-year competency-based course focused on criminal law, investigative methods, interviewing techniques and brief preparation.
Another path to becoming a criminal investigator is by gaining experience in law enforcement, in addition to completing a criminology, criminal justice or forensic science degree.
Completing a Degree
A common misconception is that you don't need to have a bachelor degree in criminology and criminal justice to become a criminal investigator. This is incorrect. The completion of a relevant degree is required to become a qualified criminal investigator. Many Universities and colleges across Australia, including ACAP University College and Open Universities AU offer criminal law degrees focusing on criminology and criminal justice which is what is usually required as a pre-requisite to becoming a detective in criminal investigations.
The common pathway to becoming a criminal investigator is by completing a Bachelor of Criminology and Justice or an Associate Degree of Criminal Justice. These courses provide a strong foundation in law enforcement, and investigation skills.
Training and Suitability Assessments
Some Australian jurisdictions require the satisfactory completion of additional training courses, such as an advanced diploma of police investigations or Bachelor of Policing (investigations) to gain the requisite skills in criminal investigations. In addition, These jurisdictions also require you to pass a investigator suitability assessment exam as a further pre-requisite.
Experience
Experience in law enforcement is usually a further pre-requisite to becoming a criminal investigator detective. You can gain this experience from working as a police officer. Working as a trainee criminal investigator detective while studying can also be very effective to fast-track a career in criminal investigation.
The Role of a Detective Criminal Investigator
Detectives will generally conduct their criminal investigations in the following forms:
- Crime scene investigation and reconstruction;
- Interviews and statement taking;
- Surveillance and intelligence gathering;
- Building evidence against a suspect; and
- Assisting in the prosecution of a suspect at trial.
Crime Scene Investigation
If a serious crime has occurred, a crime scene will often be attended by detectives in order to assess the initial evidence of a crime.
Their first responsibility of a police officer at a scene is to secure the crime scene as soon as possible. This involves establishing a perimeter to prevent contamination, documenting the scene through photos and sketches and coordinating with forensic experts. Investigators work closely with crime scene examiners, forensic pathologists and other forensic experts to collect and log physical evidence such as blood, fingerprints, hair fibres, weapons or tyre marks.
The key function of a crime scene investigation is to reconstruct the sequence of events by interpreting physical evidence and witness accounts to form a theory about how the crime occurred, and by whom.
Interviews and Statement Taking
Interviewing a witness or victim is the cornerstone of criminal investigations, and a key task undertaken by detectives.
Interviews are conducted in order to obtain written statements detailing what the person saw, heard, or experienced. Investigators must remain neutral, avoid leading questions and ensure the statement is signed under oath (a jurat).
These statements will form key part of the brief of evidence which will be handed to prosecutors to prosecute a suspect at trial.
If a suspect is identified, detectives will undertake an interview usually with the aim of either obtaining a confession or an alibi or other exculpatory evidence. In NSW, suspects must be formally cautioned before questioning. They also have the right to:
- Remain silent
- Access a lawyer
- Request an interpreter
- Have a support person present if they are a minor or vulnerable
Surveillance and Intelligence Gathering
Surveillance and intelligence gathering are also essential components of a detective's investigative toolkit, particularly in the investigation of serious indictable offences such as drug trafficking, organised crime, terrorism and high-level fraud.
Surveillance can be either covert (secret) or overt (visible), and detectives may be involved in both forms depending on the operational requirements. Covert surveillance is often used to monitor suspects without their knowledge, allowing detectives to gather information on movements, associations, and patterns of behaviour. In some cases this may involve covert (and in some cases 'controlled') operations where officers se of assumed identities and go 'undercover'.
In addition to surveillance, detectives play a central role in criminal intelligence gathering and analysis. They receive, assess, and contribute to intelligence reports generated by various sources, including:
- Community tip-offs and Crime Stoppers reports;
- Informants (human sources);
- Inter-agency intelligence (e.g., Australian Federal Police, Australian Border Force, ACIC);
- Digital data such as open-source intelligence (OSINT) and data from seized devices;
Building Evidence Against A Suspect
A core part of a detective's role is gathering and analysing evidence – physical, forensic, digital and testimonial – to compile briefs of evidence. These briefs are used by prosecutors to determine whether charges should be laid or proceeded with in court.
Criminal investigators are tasked with identifying suspects and testing their hypotheses against available evidence. There is no fixed threshold when sufficient evidence is gathered, but common key threads include:
- Unexplained forensic links between the suspect and the scene (e.g. DNA or fingerprints);
- Eyewitness testimony or CCTV footage;
- A lack of alibi for the relevant time frame;
- Suspicious behaviour before or after the crime (e.g. attempts to clean a scene or dispose of evidence); or
- A confession or partial admission.
Providing Evidence to the Prosecution and Giving Evidence in Court
After having gathered and verified all the evidence following a comprehensive criminal investigation, the evidence is then served to the prosecution, namely the Director of Public Prosecutions (DPP). The DPP have a duty to then serve the same evidence to the defence whether or not it assists the prosecution case.
However, criminal investigators still play a role in conducting further investigations to assist prosecutors as well as by giving testimonial evidence under oath at trial regarding their investigation. This is a form of expert evidence adduced by the prosecution to try to strengthen the prosecution case against the accused.
The content of this article is intended to provide a general guide to the subject matter. Specialist advice should be sought about your specific circumstances.
