Detective

In many other police systems, detectives are college graduates who join directly from civilian life without first serving as uniformed officers.

Citizen detectives can also help law enforcement by becoming witnesses for prosecutors, participating in local neighborhood watch groups, acting as citizen observers for law enforcement, or even aiding the police in searching for and arresting suspects as a posse.

However, there have been cases of citizen detectives unintentionally compromising investigations if they lack real crime solving skills or even committing acts against suspected criminals that could be deemed vigilantism in nature.

Criminal activity can relate to road use such as speeding, drunk driving, or to matters such as theft, drug distribution, assault, fraud, etc.

In criminal investigations, once a detective has suspects in mind, the next step is to produce evidence that will stand up in a court of law.

In some countries, detectives may lie, mislead and psychologically pressure a suspect into an admission or confession as long as they do this within procedural boundaries and without the threat of violence or promises outside their control.

This is not permitted in England and Wales, where interview of suspects and witnesses is governed by the Police and Criminal Evidence Act 1984 and its extensive Codes of Practice.

Many major police stations in a city, county, or state, maintain their own forensic laboratories while others contract out the services.

Detectives may search through records of criminal arrests and convictions, photographs or "mug shots" of persons arrested, hotel registration information, credit reports, answering machine messages, phone conversations, surveillance camera footage, and technology used for communication.

Before 2017, prospective British police detectives must have completed at least two years as a uniformed officer before applying to join the Criminal Investigation Department.

[13] Before becoming a police detective, one must attend a law enforcement academy, which provides the officer with a foundation of education with 16 to 24 college units.

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.

In Vietnam, private detective work is not yet officially recognized by law but is developing due to the demands of modern society.

[16][17][18] However, many detective companies have made efforts to provide professional services, adhering to ethical standards and legal regulations to build trust with clients.

Police detectives investigating a homicide in Oklahoma City , Oklahoma , United States
H Division, of police detectives, including Frederick Abberline (left, with cane), at Leman Street police station, of the London Metropolitan Police , two years before the Jack the Ripper serial killer murders of 1888. Photograph circa 1886
Allan Pinkerton (pictured here circa 1861) was, in 1850, a detective of the Chicago Police Department and, in 1851, the founder of the Pinkerton Detective Agency .
Edward Bonney , an American bounty hunter and amateur detective from Iowa who in 1845 infiltrated the " Banditti of the Prairie ", wrote the 1850 book The Banditti of the Prairies: or, The murderer's doom, a tale of Mississippi Valley and the Far West ; woodcut from 1850.
Detectives of the West Midlands Police in the United Kingdom surrounded by electronic devices seized as evidence
Detective escorting gangster Meyer Lansky to the 54th Street police station in New York City in 1958