Matheny was employed as a reserve deputy sheriff by the Putnam County Sheriff’s Department during 1990 and 1991, and then began worked as a full-time police officer with the City of Baxter, Tennessee from 1991 through 1993, before becoming a special agent for the Tennessee Alcoholic Beverage Commission, where he worked within many liquor and narcotic related duties from 1994 to 1998.

In 1998, Matheny founded Advanced Protective Services, Inc., which specialized in private investigations, executive protection, electronic surveillance and counter-surveillance, training and security consulting to a number of prominent corporations doing business in the Nashville, Tennessee area and employed approximately thirty full-time, armed guards and about "250 police officers in an off-duty, uniformed capacity."

[1] Matheny was chairman of the Coffee County Republican Party[2][3] and was also a member of the Chambers of Commerce of Tullahoma, Manchester, and McMinnville.

[10] On April 2, 2024, Matheny was found dead inside a vehicle in the driveway of his Coffee County home.

[12] On May 15, 2024, County Medical Examiner Jay M. Trussler reported that a mixture of cocaine, alcohol and Kratom contributed to his death.