Merice Brown, 31, has been sentenced to 12 years in prison for shooting another man in a Kennington barber's shop in 2005.
Ten years later Brown walked into Braunstone Police Station in Leicestershire and stated that he wanted to clear his conscience and admitted to committing the shooting.
He told officers he had found religion and wished to own up to his crimes.
It's understood he is a born again Christian.
Inner London Crown Court was told how Brown was riding his bike in Camberwell New Road, Kennington on 3 March 2005 when he saw a 19-year-old man sitting in a barber shop having his hair cut.
Brown and the man made eye contact and started staring at each other. Brown then went into the barber's shop and sat in a chair next to the man and they continued to stare at each other. There was then an exchange of words and Brown left the shop.
A few minutes later he came back and shot the victim a number of times before riding off on his bike.
After admitting his crime the man described where he buried the gun and pointed out the location using Google maps.
Met Police discovered a black semi-automatic hand gun exactly where he had said.