Sheriff Frank Denning has dedicated his career to law enforcement. For over 42 years he has been serving the citizens of Kansas as a law enforcement officer. His career began in 1969 as a Reserve Police Officer for the Great Bend Police Department, and for the past 33 years he has proudly served the citizens of Johnson County.
Sheriff Denning served with the Great Bend, Larned and Garden City Police Departments before joining the Johnson County Sheriff's Office in 1978. During his time with the Sheriff's Office he worked as a Deputy serving in the Adult Detention Center, Patrol, Investigations and Narcotics Divisions before being promoted to Sergeant and Lieutenant.
Sheriff Denning left the Sheriff's Office in 1996, to become the Chief of Police with the City of Roeland Park, Kansas. He served as Roeland Park Police Chief until his return to the Sheriff’s Office in August of 2002, when then Sheriff John Foster appointed him as Undersheriff. Denning would serve in this role until April of 2003.
In 2004, the people of Johnson County elected Denning as their 27th Sheriff. In 2008 he was reelected to the Office of Sheriff. Under his leadership, a new state of the art, nationally accredited, full service forensic Criminalistics Laboratory was completed in 2012 to serve all Johnson County communities, along with partnerships with the KBI and KCMO PD Crime Labs.
Through his time as Sheriff, Denning has led the office to become change agents in the criminal justice community. His leadership has propelled Johnson County forward to adopt thought and practice changes on reducing recidivism through Second Chance and Reentry programs.
Sheriff Denning is a graduate of Ottawa University with a Bachelor’s Degree in Administration of Justice. He is a graduate of the 196th Class of the FBI National Academy and a current member of the Kansas-Western Missouri chapter of National Academy graduates. He is a life member of the Kansas Peace Officers Association, having served as President and Governor Emeritus. In addition he is a member of the Kansas City Metropolitan Chiefs and Sheriffs Association, the Johnson County Chiefs and Sheriff's Association, the Kansas Sheriffs' Association and the International Association of Chiefs of Police.
Sheriff Denning is married to Robin Lewis, a former Johnson County Prosecutor and current private practice attorney in Johnson County.