The City of Peekskill Police Department Detective Division is comprised of two units, General Investigations and Narcotics. Detectives who are assigned to the General Investigations Unit (GIU) are responsible for investigating all reported felony offenses. In addition, GIU Detectives are trained to process crime scenes and collect evidence, follow up on missing persons reports, attempt to locate and arrest those with outstanding arrest warrants, conduct pre-employment background investigations, and provide support to the other units in the police department.

Detectives assigned to the Narcotics Unit are tasked with conducting undercover investigations targetting illegal drug dealers at all levels. They frequently work with other agencies at the local, county, state, and federal level with great success. In addition, those assigned to the Narcotics Unit provide support to the General Investigations Unit in major cases and are trained in crime scene processing and evidence collection.