A criminal investigator is a law enforcement professional who attempts to solve crimes, identify and detain suspects, and prevent future instances of criminal activity. Professionals may work alone or in investigative teams to uncover facts about a case. An investigator may specialize in analyzing evidence and information from a crime scene, conducting interviews and searches, or performing surveillance. Depending on a person's specialty, the responsibilities and requirements of the job can range greatly.
Experts who specialize in crime scene investigation are often degree-holding laboratory technicians and technologists who work to uncover the details of a crime. Crime scene investigators may carefully examine a scene and collect evidence such as weapons, clothing samples, and fingerprints. Investigators frequently bring the evidence to a laboratory for intensive studies and experimentation. Among many tasks, they may determine ballistics information by performing firearm evaluations or confirm identities by extracting DNA from clothing samples. They write reports based on their findings and frequently appear in courts as expert witnesses.
Some criminal investigators engage in covert surveillance operations to expose criminal activity. Such investigators may install and monitor surveillance equipment or wear disguises to find out more about a suspicious person or organization. They may be required to follow suspects, carefully documenting their whereabouts and conversations. Investigators may also spend a large amount of time tracing phone calls and performing exhaustive background checks and Internet database searches.
When a suspect is detained, a investigator often interrogates him or her to find out more facts about a case. Investigators may also interview witnesses and other people who may have relevant knowledge about the suspect or crime scene. After obtaining a search warrant, a team may explore a suspect's home, business, or property. Searches frequently reveal new pieces of evidence, such as stolen items, money, letters, and weapons, that confirm a suspect is involved with a crime.
To become a criminal investigator, a person must typically have at least a high school diploma or GED. Most police bureaus at local, state, and federal levels of government prefer to hire candidates with bachelor's degrees and experience in the field. Since many crime scene professionals perform laboratory research, they benefit from obtaining computer science, biology, and chemistry degrees. A degree in criminal justice or police science is helpful to other types of jobs. Those with previous law enforcement, security, or military experience generally have better chances of obtaining work in this profession.