A criminal investigator is a professional who takes part in the study and analysis of crime in order to catch criminals and prevent future crimes. There are many different types of criminal investigator jobs, which allow both privately operating and public law-enforcement investigators to tailor their careers around their personal education. Criminal investigator jobs may range through all areas of the criminal justice system, from laboratory analysis to testifying as an expert witness.
Education may determine what type of criminal investigator jobs a professional is suited to perform. Those with a background in biology chemistry may be drawn to jobs that require them to scientifically analyze evidence. This work can help determine the presence of DNA or the chemical composition of substances like drugs or explosives. Working as an analyst may not sound as glamorous as chasing criminals through the moonlit streets, but is the critical step that helps turn raw evidence into a criminal case. Criminal investigator jobs that focus on laboratory or forensic analysis may be available through law enforcement agencies or private companies.
Private criminal investigators may also be called private detectives or private eyes, and have the advantage of choosing their own clients and cases. Many provide services such as background checks, surveillance, and tracking down missing persons. Though there may not be a required educational background for private criminal investigator jobs, many regions have specific licensing requirements, including written tests. Private investigators are often retired law enforcement personnel, and many work closely with law enforcement operations to conduct surveillance and stings.
A crime scene investigator visits locations where crimes are believed to have occurred and searches for salient details that may provide evidence. These professionals often have a background in criminal justice, and must have a keen sense of analysis in order to seek out important details and ignore trivial ones. Crime scene investigator jobs also require that a professional follow all necessary legal guidelines that concern the handling and examination of evidence. If evidence is contaminated, obtained illegally, or incorrectly handled, it may be thrown out by the court as inadmissible and result in the dismissal of important cases.
Both private and law enforcement affiliated investigators may take on supplemental work as expert witnesses. This allows them to serve as paid consultants brought on by lawyers to offer a professional opinion or provide testimony based on an independent analysis of crime scene data. Expert witnesses need to have a long history of experience and an excellent reputation, in order for their opinion to be given due weight by the court.