Tharp began his career as a police officer in
Berkeley and
Overland, Missouri. He then joined the Madison County Sheriff's Office, serving as a deputy sheriff from 1999 to 2004, detective from 2004 to 2009, and sergeant from 2009 to 2011. From 2013 to 2015, he was an investigator for the Southern Illinois Child Death Investigation Task Force. From 2012 to 2020, he served as a lieutenant in the Madison County Sheriff's Office. In 2019, he was appointed to serve as a member of the Illinois Elder Abuse Task Force. Tharp also served as a supervisor of the Major Case Squad of Greater St. Louis and jail administrator in the Madison County Sheriff's Office. On July 8, 2022, Tharp was appointed to succeed
Rachelle Crowe in the
Illinois Senate after Crowe was confirmed as a
United States attorney. == Personal life ==