According to NYPD Department policy, Members of the Service are prohibited from being assigned to work within the confines of their residential precinct except for school crossing guards and civilians who began working for the NYPD before July 2009. The rationale behind the rule, to avoid conflicts of interest, perceived or otherwise. That being said, as a matter of good Community Policing Policy, a member of the general public is less like to take an adversarial stance in an interaction with a police officer, if it is a person they know very well
According to the US Supreme Court Ruling, Frazier v. Cupp (1969), the police are within their rights to use trickery, including outright lying, to provoke a confession.