Detectives are plainclothes police officers who work to solve various crimes on a municipal level. Contrary to patrol officers, who may intervene in a case only long enough to bring it to the department's attention, detectives are usually assigned to a specific case, working on it until it is closed or dropped. Thus, detectives often specialize in crimes such as homicide or burglary.

While working on a case, detectives may use a variety of methods. These can include:

• Reviewing previous cases
• Interviewing witnesses
• Surveying crime scenes
• Uncovering and handling evidence
• Making arrests
• Tracking or monitoring suspects