June 4, 2024
TRENTON, NJ (MERCER)–Mercer County Prosecutor Angelo J. Onofri and Chief of Detectives Jessica Plumeri are proud to announce the promotions of Brian Kiely to deputy chief, Nancy Diaz to captain, Richard Sheppard to lieutenant and Ahmad Mansur to sergeant. With her oath of office, Capt. Diaz became the highest-ranking Latina in Mercer County law enforcement history.
Deputy Chief Kiely began his law enforcement career in 1999 as a civil investigator at the Division of Criminal Justice after graduating from John Jay College of Criminal Justice. In 2000, he became a criminal investigator with the state DCJ, investigating organized crime, money laundering and narcotics. He spent a year assigned to Newark Liberty International Airport as part of a U.S. Customs Narcotics Interdiction Task Force.
In 2006, Deputy Chief Kiely joined the Mercer County Prosecutor’s Office, where he has spent a large part of his career dedicated to narcotics investigation. He is an expert witness in the field of narcotics trafficking and his work has helped secure convictions in homicide, racketeering and narcotics trafficking cases. In 2021, he was designated as the chief humane law enforcement officer.
Deputy Chief Kiely has supervised most units in the office, including every unit in major crimes. He has spent his career as a police instructor at the Mercer County Police Academy and the New Jersey Division of Criminal Justice. He is responsible for updating the written policies and procedures of the prosecutor’s office, and the procurement of equipment. He manages several ongoing projects that keep the prosecutor’s office at the forefront of law enforcement technology.
