A Convicted Cop Killer Has Appeared In Sullivan County Criminal Court. A Status Hearing Was Held Yesterday For Nickolus Johnson Who Was Convicted Of Killing Bristol, Tennessee Police Officer Mark Vance In November 2004. Johnson Was Supposed To Be Executed Last April, But Was Granted Post Conviction Relief Last March, Meaning His Conviction Is Being Reviewed. The Defense Alleges Errors And Constitutional Issues Violation In The Case. A Hearing Is Set For July 17th.