A murder charge against the suspect in a nightclub shooting trial has been dropped after two of the victim's friends refused to give evidence.
Mr Cope was shot outside a nightclub
A witness claimed victim Damian Cope named Andrew Wanoghu, 25, as his killer as he lay dying in July 2002.
But the court heard two friends would not give evidence and other evidence cast doubt on the "dying declaration".
Mr Cope's mother Lucy, founder of an anti-guns charity, collapsed in tears as Mr Wanoghu walked free.
After her son was shot dead outside Browns club in Holborn, central London, Mrs Cope set up Mothers Against Guns.
The influential charity campaigned for tougher sentences for gun crimes.
Outside court she condemned the "cowardice" of witnesses who would not give evidence.
Mrs Cope said: "I am devastated. Nothing can heal my broken heart.
"I will come back with a vengeance and campaign to have the double-jeopardy laws changed."
The double jeopardy rule states that, in English law, anyone cleared of a crime in court cannot be retried for the same crime at a later date.
Richard Horwell, prosecuting, told the court Mr Cope was shot in the abdomen in the street and had run 50 yards back to the club where he collapsed.
A witness had claimed he spoke to the victim within moments of his collapse and he had identified his killer.
But the witness did not give his name and refused to give a statement to police.
In February last year a second witness came forward who claimed he had spoken to Mr Cope seven-and-a-half minutes after his collapse and said he had named
Mr Wanoghu as his attacker.
Mr Howell said the case against Mr Wanoghu was based on the "dying declaration" to this witness who was now not prepared to come to court.
"There is no doubt that he is in fear," said Mr Horwell.
The prosecution decided not to proceed because his statement had been brought into doubt by medical evidence.
It showed it would have been "unlikely in the extreme" that Mr Cope could have spoken to him when he said.
A bouncer had also been with Mr Cope all the time and was prepared to testify that the victim "did not utter a word" after collapsing.
The Common Serjeant of London Judge Peter Beaumont told the prosecution: "The step you have taken is entirely responsible."
Mr Wanoghu, of Gisterwood Street, Deptford, south-east London, had denied shooting Mr Cope.