Detectives and investigators gather facts and evidence for criminal cases.

Detectives and investigators work for:

• State police
• Local police
• Federal agencies

The specific tasks of detectives and investigators depend on the size and type of the agency they work for. A detective or investigator on a small city police force performs very different tasks than an FBI agent. However, all detectives and investigators have many duties in common.

Detectives and investigators receive cases and gather data. They interview witnesses, suspects, and others who might have information. They review and analyze records and case files.

Some detectives and investigators visit crime scenes to find fingerprints and collect other evidence. This can include blood, hair, fibers, or weapons. They make sure that evidence is not disturbed. They keep potential suspects and witnesses at the scene. They may take them into custody or interview them. Detectives and investigators also take photographs of the crime scene.

Detectives and investigators may observe the activities of suspects without their knowledge. Sometimes detectives get court orders for searches or wiretaps. They keep files on suspects and write reports of their findings. Records must be detailed and accurate since they are often used in court. They make arrests when they have enough evidence to prosecute suspects. They often testify before the court or a grand jury.