As Sheriff, Gallivan authored and implemented a comprehensive six-point strategic plan, which charted the course for the professional, ethical, cost-effective and community-oriented delivery of criminal justice services by the Erie County Sheriff's Office. He reorganized the agency and oversaw the merger of the Erie County Holding Center and the Erie County Correctional Facility.

Before being elected Sheriff, Gallivan served 15 years in the New York State Police, rising through the ranks from Trooper to Captain. He is a graduate of both the prestigious FBI National Executive Institute and the FBI National Academy, and is a past member of the New York State Executive Committee on Counter-Terrorism.

Gallivan is also a small business owner, founding and operating a full service professional investigation and security firm. In addition, Gallivan previously served as a Member of the New York State Board of Parole. He holds a master's degree in Criminal Justice from the State University of New York at Albany and is a graduate of Canisius College in Buffalo. Gallivan has also received numerous awards and honors for his long and distinguished service to the community and has served numerous professional, charitable, civic and fraternal organizations. Senator Gallivan lives in Elma with his wife, Mary Pat. They have two children, Jenna and Conor.