Castellano, Costello promoted to top detective positions at Morris County Prosecutor’s Office

MORRISTOWN, N.J. (Morris County) — The Morris County Prosecutor’s Office has promoted Mark Castellano to acting chief of detectives and Joseph Costello to acting deputy chief of detectives, Prosecutor Robert J. Carroll and First Assistant Prosecutor Maggie Calderwood announced.

A formal swearing-in ceremony will be held at a later date.

Castellano is a 27-year law enforcement veteran who began his career with the Hudson County Prosecutor’s Office, where he was assigned to the Narcotics Task Force. He joined the Morris County Prosecutor’s Office in 2002.

During his tenure, Castellano has served in the Narcotics, Fugitive, Intelligence/Gang, Community Affairs, Juvenile/Missing Persons, General Investigations and Training/Firearms units. He has also been a member of the Tactical Narcotics Team and Rapid Deployment Team.

Castellano is a New Jersey Police Training Commission certified instructor, master resiliency trainer, training coordinator and supervising firearms instructor. He has provided instruction to law enforcement personnel and other public safety professionals domestically and internationally.

He is a Seton Hall University graduate and recipient of the FBI-LEEDA Trilogy Award.

Costello has more than 25 years of law enforcement experience. He began his career with the Sussex County Prosecutor’s Office before joining the Morris County Prosecutor’s Office in 2006.

Costello has served in investigative, supervisory, tactical and command assignments involving Major Crimes, Sex Crimes, Intelligence, Narcotics, Homeland Security, Specialized Crimes and Special Operations.

He is a graduate of the FBI National Academy and an Accredited Command Executive through the New Jersey State Association of Chiefs of Police. Costello holds a Master of Arts in Human Resources Training and Development from Seton Hall University, a Graduate Certificate in Criminal Justice Education from the University of Virginia and a Bachelor of Arts in Administration of Justice from Salve Regina University.

“I am excited that we are able to fill these important executive leadership positions with career law enforcement professionals who have demonstrated their skills, knowledge, commitment, and integrity to protecting the citizens of Morris County. I have been blessed to have worked for decades with excellent police leaders, and both Chief Castellano and Deputy Chief Costello have displayed those qualities, which will provide a firm foundation to continue the exceptional reputation of the MCPO in all areas of criminal investigation and prosecution. I look forward to working with them in our unified mission of achieving justice for all victims, and apprehending those responsible for committing criminal activity,” Carroll said.

Calderwood also congratulated Castellano and Costello on their promotions.

“I want to extend my warmest and most sincere congratulations to Chief Mark Castellano and Deputy Chief Joe Costello. Having had the privilege of working alongside both for decades, I have witnessed their dedication, skills, and leadership. Their promotions are a testament to all their hard work and commitment to the Morris County Prosecutor’s Office and the entire Morris County law enforcement community. I wish you both continued success in your new roles!” Calderwood said.