Dimakatso Mametsa pleaded guilty to a charge of murder and two other crimes when he appeared in the Attridgeville Magistrates Court on Thursday.
Constable Ronald Baloyi was off duty when he was gunned down in a confrontation with Mametsa in August this year.
The National Prosecuting Authority’s Luvuyo Mfaku says the conviction should serve as a clear message to criminals.