A lifelong resident of Broome County, Gary O’Neill grew up in Johnson City, with his parents, Frank and Mary and sisters, Sharon, Rosemary, and Deborah. He graduated from Catholic Central High School in Binghamton and holds two degrees from Broome Community College, one in Liberal Arts and one in Criminal Justice.

In 1974, Gary joined the Endicott Police Department as a patrol officer. After ten years of service he was promoted to Patrol Sergeant and rose through the ranks serving as a Detective, Patrol Lieutenant, Detective Lieutenant, Captain, and from 1994-2004 Chief of Police. 

While he was a Sergeant with the Endicott Police Department, Gary was selected to attend the FBI National Academy and is a graduate of the 151st Class. Participation in the FBI National Academy’s program is an honor extended by invitation only, through a nomination process.

In 2004, Gary became the Broome County Undersheriff and served in that capacity with Sheriff Harder until resigning in 2010 to run for the office of Broome County Sheriff. He remains a longstanding member of the FBI-Law Enforcement Executive Development Association and the International Association of Chiefs of Police. Gary is currently working for Broome County Government Security as a Parks Supervisor.

Serving his community has always been a priority to Gary, whether it is on the job as a career law enforcement officer, or through active participation in local volunteer organizations. Currently, Gary is the Chairman of the Board of Trustees for Endicott Sertoma, and a member of the Family Violence Prevention Council, Our Lady of Good Counsel Church in Endicott, the Southern Tier Soccer Officials Association, and the Ancient Order of Hibernians.

Gary and his wife Trish live in Endicott. His daughter and son-in-law Ellen and Joe Saunders, and their two boys, Luke & Levi, live in Owego.  Gary’s son Jared, daughter-in-law Valerie, and granddaughter Evelyn live in Johnson City.