Kelly Stone began his career in law enforcement in 1974 as a Patrol Officer. In 1985, he joined the Collin County Sheriff's Office where his duties included Tactical Operations Team/Field Training Officer, Criminal investigator, DEA Task Force, Group 2. Five years later, he was promoted to the rank of Sergeant in charge of Internal Affairs and Training. In 1991, he was promoted to Captain over Operations and later promoted to the rank of Major, a position he served in until November 2002. Collin County Commissioners Court appointed him the county's first Director of Homeland Security In November 2002.

Stone has a Master Peace Officer Certificate and Law Enforcement Instructor Certificate. He also received his Bachelor of Business Management from LeTourneau University and his Master of Business Administration from The University of Texas at Dallas. Currently, he is enrolled in a PhD program at UTD in Public Affairs. His education and law enforcement training include: Graduate of the 189th Session of the FBI National Academy at Quantico, Virginia and Law Enforcement Command College at Sam Houston University.

As Director of Homeland Security, Stone is responsible for courthouse and county facility security, the Fire Marshal's office, bioterrorism planning and response, as well as Collin County's Emergency Management.