By: Najla Alexander
Mercer County officials 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.
Officials stated 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, officials say, 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, officials said.
Authorities say he was designated the chief humane law enforcement officer in 2021. Deputy Chief Kiely has supervised most units in the office, including every unit involved in major crimes. He has also spent his career as a police instructor at the Mercer County Police Academy and the New Jersey Division of Criminal Justice.
Officials say he is responsible for updating the prosecutor’s office’s written policies and procedures, and the equipment procurement. He manages several ongoing projects that keep the prosecutor’s office at the forefront of law enforcement technology. Deputy Chief Kiely supervises the Community Outreach and Restorative Justice units.
He often volunteers his time at community events, including the Special Olympics, officials stated, and he has been a volunteer for the Boy Scouts of America for many years, serving as an Eagle Scout advisor and scoutmaster of Troop 180A.
A graduate of the InterAmerican University of Puerto Rico with a bachelor’s degree in criminal justice, Capt. Nancy Diaz began her career in law enforcement in 1998 as a juvenile officer for the Trenton Police Department, officials said.
According to officials, she joined the New Jersey Division of Criminal Justice Office of the Insurance Fraud Prosecutor in 2001 as a civil investigator and graduated from the New Jersey Division of Criminal Justice Police Academy in 2003. Capt. Diaz joined the Mercer County Prosecutor’s Office in 2005 and has worked in every unit throughout her career.
She has served as a physical training instructor at the Mercer County Police Academy and was also a coordinator for the Mercer County Child Abduction Response Team, officials stated.
In 2018, officials say, Capt. Diaz was the lead detective in the Art All Night shooting investigation where two gunmen opened fire at a 24-hour annual community arts event and music festival in the City of Trenton, resulting in the death of one of the gunmen and injuries to 22 people.
According to officials, she was promoted to sergeant that same year, becoming the first Latina sergeant in the history of the Mercer County Prosecutor’s Office. She has supervised the Mercer County Homicide Task Force, the Serious Collision Response Team, the Shooting Response Team, and numerous other MCPO units, including Computer Crimes, Domestic Violence, Economic Crime, and Internal Affairs. Capt. Diaz was promoted to lieutenant in 2023 and recently celebrated her 25th year in law enforcement.
She is proudly supported from day one of her career by her husband of 26 years, Jesse, and their 13-year-old daughter, Arianny, authorities say.
Lt. Richard Sheppard joined the Mercer County Prosecutor’s Office in 2010 after graduating from the New Jersey Division of Criminal Justice Academy.
Officials say after working in the Trial Unit for two years, he was assigned to the Special Investigations Unit/Mercer County Narcotics Task Force (SIU/MCNTF) for seven years before joining the Mercer County Homicide Task Force. He was promoted to sergeant in 2021 and has supervised the Special Victims and Internet Crimes Against Children (ICAC) units as well as the SIU/MCNTF.
During his law enforcement career, officials said, Lt. Sheppard has handled several high-profile homicide and narcotics investigations, including multiple homicide investigations involving the “H-Block” gang that has led to several convictions.
Officials said he has also participated in and led several narcotics operations throughout the state of New Jersey. Lt. Sheppard has served as vice president of PBA Local #339 and is currently president of the Superior Officers Association.
Lt. Sheppard is a certified instructor with the New Jersey Police Training Commission and instructs at several narcotics schools, including New Jersey State Police/FBI Undercover Training, the Undercover Narcotics Investigations Training (UNIT), and Top Gun, authorities say.
Officials say he is also a certified firearms instructor with the state Division of Criminal Justice and instructs for the Mercer County Prosecutor’s Office and the Mercer County Police Academy. Born and raised in Trenton, Sgt. Ahmad Mansur began his law enforcement career with the Trenton Police Department in February 2006.
Officials said upon completing the Trenton Police Academy, he was assigned to the Patrol Bureau and then the Detective Bureau. In 2012, Sgt. Mansur joined the Mercer County Prosecutor’s Office and has worked in the Grand Jury, Trial, Special Victim, Insurance Fraud, and Domestic Violence units.
He has also been assigned to the Mercer County Shooting Response Team and the Mercer County Homicide Task Force. Following a promotion to officer in charge in June 2022, Sgt. Mansur was assigned to the Special Victims and Internet Crimes Against Children (ICAC) units, where he oversaw the day-to-day investigations and operations of the ICAC Unit, officials said.
According to officials, he has undergone extensive ICAC supervisor training provided by the New Jersey State Police and has also served as coordinator of the Child Abduction Response Team. Over the last several years, Sgt. Mansur has taught various courses at the Mercer County Police Academy. He is an emergency vehicle operation course and physical fitness instructor and oversees academy scenario operations.
During his tenure at the Mercer County Prosecutor’s Office, officials said, he served as vice president and president for PBA Local #339. As an advocate for the City of Trenton, Sgt. Mansur is actively engaged in the community, attending various meetings and acting as an outreach advocate for city youth in the Trenton Public School System.
The promotions follow the June 1 retirement of Deputy Chief Bryan Cottrell, officials stated.