<P> Detective - Investigators are the type most people associate with the term "detective" and are the ones most frequently portrayed on television and in the movies . Most police officers gain their detective title by working in the Narcotics Division of the Detective Bureau . Detectives assigned to squads are co-located within each precinct and are responsible for investigating murders, rapes, robberies, burglaries and other crimes within that precinct's boundaries . Other detective - investigators are assigned to specialized units at either the major command or citywide level, investigating terrorist groups, organized crime, narcotics dealing, extortion, bias crimes, political corruption, kidnappings, major frauds or thefts committed against banks or museums, police corruption, contractor fraud and other complex, politically sensitive or high - profile cases . A squad of detective - investigators is also assigned to each of the city's five district attorneys' offices . (Arsons are investigated by The Arson and Explosion Squad as well as fire marshals, who are part of the New York City Fire Department .) </P> <P> Promotion from Police Officer to Detective - Investigator is based on investigative experience . Typically, a Police Officer who is assigned to investigative work for 18 months will be designated "Detective - Investigator" and receive the gold shield and pay increase commensurate with that designation . In the recent past, however, there has been controversy over the budget - conscious department compelling police officers to work past the 18 months without receiving the new title . </P> <P> Newly appointed detectives start at Detective Third Grade, which has a pay rate roughly between that of Police Officer and Sergeant . As they gain seniority and experience, they can be "promoted" to Detective Second - Grade, which has a pay grade slightly less than sergeants . Detective First - Grade is an elite designation for the department's most senior and experienced investigators and carries a pay grade slightly less than Lieutenants . All these promotions are discretionary on the part of the Commissioner and can be revoked if warranted . And while senior detectives can give directions to junior detectives in their own squads, not even the most senior detective can lawfully issue orders to even a junior patrol officer . All Detective grades still fall under the "chain of command" of the supervisory ranks beginning with Sergeant through Chief of Department . Detectives, like Police Officers, are eligible to take the promotional civil service exams for entry into the supervisory ranks . </P> <P> While carrying with them increased pay and prestige, none of these Detective grades confer on the holder any supervisory authority . Contrary to some media portrayals, there is no specific rank of "Detective Sergeant" or "Detective Lieutenant". Lieutenants and Sergeants are assigned to oversee Detective squads as Supervisors, and are responsible for all investigations . </P>

How many first grade detectives in the nypd