page_title: Detective
section_title: United States
hierarchical_section_title: Detective / Across the world / United States
caption_attribution_description: Meyer Lansky being led by detective Jeremiah Mullane for booking on vagrancy charge at 54th Street police station, New York City
context_page_description: A detective is an investigator, usually a member of a law enforcement agency. They often collect information to solve crimes by talking to witnesses and informants, collecting physical evidence, or searching records in databases. This leads them to arrest criminals and enable them to be convicted in court. A detective may work for the police or privately.
context_section_description: Before becoming a police detective, one must attend a law enforcement academy, providing the officer with a foundation of education with 16 to 24 college units in criminal justice or administration of criminal justice. After graduation from the law enforcement academy, the officer undergoes job training with a field training officer for a period specified by the law enforcement agency and continues to work while on a probationary period, ranging from one to two years.
  During the probationary period, the officer is assigned to look for evidence. During this time, the officer is supervised and mentored by a sergeant with years of experience. Some officers further their college education by attending a two- or four-year college or university, attaining a degree in criminal justice or administration of criminal justice. Colleges have options for a concentration or certificate in a specialized field of criminal investigation.
  Through years of on-the-job training or college education, officers may participate in a competitive examination, testing their knowledge, skills and abilities regarding criminal investigation, criminal procedure, interview and interrogation, search and seizure, collection and preservation of evidence, investigative report writing, criminal law, court procedure and providing testimony in court. Competitive examinations are conducted by selected senior law enforcement officials. Following testing, a list of results is provided by the department. At the department's discretion, some or all of the officers on the list are promoted to the rank of detective. Some departments have classes of detectives which increase the detective's rank after successful experience.
  Private investigators are licensed by the state in which they work (some states do not require licensing, but most do). In addition to the state examination, applicants testing for a private investigation license must also meet stringent requirements, which include college education, a range of two to four years of full-time investigation experience and the successful adjudication of a criminal and civil background check conducted by state investigators. Private investigators are licensed to conduct civil and criminal investigations in the state in which they are licensed, and are protected by statutes of that state. In states requiring licensure, statutes make it unlawful for any person to conduct a criminal investigation without a license, unless exempted by the statute (i.e., law enforcement officers or agents, attorneys, paralegals, claims adjusters).
caption: Detective escorting gangster Meyer Lansky to the 54th Street police station in New York City in 1958
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