Fayette Circuit Judge Ernesto Scorsone revoked the probation of Jamar Mays, 19, of Lexington and sent him back to prison to serve his 10-year sentence.
Mays pleaded guilty to manslaughter in the 2009 shooting death of his best friend Ali Shalash, 17, of Lexington.
Mays spent two years in a juvenile facility and was paroled when he turned 18.
Mays' parole was revoked when he left the county without permission and admitted to using synthetic marijuana. Prosecutors said Mays was arrested in Madison County with a pistol in his pocket.