A gunman who murdered a bouncer and a policeman in south London more than 12 years ago has been jailed for life.
Nelson was described as having an "extraordinarily short fuse"
Gary Nelson, 36, of Woolwich, south-east London, was convicted of murdering William Danso and Pc Patrick Dunne in Clapham in October 1993.
Unarmed Pc Dunne was shot in the chest as he went to investigate the sound of gunshots at Mr Danso's home.
Nelson, who was already in prison for possessing weapons, was told he must serve at least 35 years in jail.
Mr Danso, a doorman at the Brixton Academy, had refused Nelson entry to the nightclub and, on the day he died, he was working as a part-time security guard at a shop when he broke up a fight involving Nelson.
Woolwich Crown Court heard Nelson targeted Mr Danso, 31, for "disrespecting" him.
He and two unidentified accomplices laughed as they fired a hail of bullets at father-of-four Mr Danso in his hallway in Cato Road, Clapham, on 20 October 1993.
Meanwhile beat officer Pc Dunne, 44, who had been investigating a minor domestic dispute, heard gunshots from the house opposite and went to investigate.
But as the unarmed policeman stepped into the street he was hit by a single shot to the chest, killing him instantly.
The trial heard that Nelson was a man with an "extraordinary short fuse" who murdered Mr Danso "out of wickedness and complete madness".
Jurors were also told that there was no way he could have failed to realise Pc Dunne was a policeman, as he was in full uniform and wearing a yellow reflective top.
Judge Mr Justice Wilkie said: "Each of them was unarmed and shot to death, for no reason other than they were doing their jobs.
Pc Dunne overheard the shots that killed Mr Danso
"[Nelson's] utter disregard for any civilised behaviour is reflected in the fact that they were so pleased by what they had done they were heard by a number of witnesses laughing.
"These killings were as callous as they were brutal and senseless."
Nelson gave no evidence during the five-week trial, nor was he in court to hear the jury return an unanimous verdict, which the judge attributed to "moral cowardice".
Nelson was charged with the murders just five weeks after they took place, but the case was dropped because of insufficient evidence.
But he was jailed soon after for pulling a gun on a van driver who overtook him, a month before the murders.
He was released in 1999, but jailed for life in 2004 for weapons offences. While in prison last year, he was again charged with the Clapham murders.
Referring to the length of time before any conviction, Pc Dunne's brother, Steve, a former pastor, said: "In all that time we never gave up hope - and we never stopped forgiving.
"Forgiveness is the other side of justice's coin."
Mr Danso's widow Deborah and his sister Gifty burst into tears as the jury convicted Nelson.