Mark Anthony Tony Williams was a 24-year-old Knoxville Police Department officer when he was shot three times in the back on the night of July 7, 1989. Off-duty and riding his motorcycle near the I-40 and Cherry Street interchange, he managed to leave the interstate but lost control and crashed on Cherry Street. He was taken to a hospital and pronounced dead on arrival. Williams had been with the department three years and was a former University of Tennessee football player who had given up a college scholarship to pursue law enforcement.

The original investigation focused on two men, Johnny Edgar Warwick and Larry Wayne Witt, after witnesses reported seeing them and a woman under the interstate in what was suspected to be a drug transaction shortly before the shooting.

About five years ago investigators reopened the file. Sergeant Rodney Patton, Detective Brandon Stryker and retired FBI Special Agent Paul Hughes re-examined evidence and re-interviewed Warwick, with assistance from the FBI Safe Streets Task Force. In December 2023 a Knox County Grand Jury found probable cause to charge Johnny Edgar Warwick with first-degree murder, but Warwick died in November 2023 before any criminal case could proceed. Does anyone have information about that night or the people seen under the interstate who could help confirm what happened?