A 1989 Cold Case Out Of Knoxville With Ties To Sullivan County Has Been Closed. On July 7th 1989, Off-Duty Knoxville Police Officer And Sullivan County Native, 24-Year-Old Mark Anthony, Was Shot And Killed While Riding His Motorcycle On Cherry Street In Knoxville. A Knox County Grand Jury In December Named Johnny Warwick As The Suspected Killer. Warwick Died In November Of Last Year. Williams Was A 1982 Graduate Of Sullivan Central High School.