A Tyneside man who has spent more than 14 years in prison for a revenge murder has said he is "overwhelmed" after his conviction was quashed.
Mr Adams will not face a retrial, said the Crown Prosecution Service
Andrew Adams, now 36, was convicted in 1993 of shooting former science teacher Jack Royal on the doorstep of his Gateshead home in 1990.
His trial was told he believed Mr Royal had stabbed another man to death.
The Court of Appeal said his conviction was unsafe because defence lawyers did not use all of the evidence available.
The CPS later said Mr Adams, of Chapel Park, Newcastle, would not face a retrial.
A spokesman for Northumbria Police said the force accepted the Court's findings but would not comment further until they had been studied in detail.
Mr Adams, who was aged 23 at the time of the trial, said after his conviction was quashed: "I am overwhelmed with all that has happened.
"A few minutes ago I was a prisoner serving a life sentence for a crime I did not commit. I am now a free man."
"I will now return to Newcastle and begin to rebuild the life I once had."
His solicitor, Ben Rose, said: "It is a shameful day because the material which has led the Court of Appeal to quash Mr Adams conviction was there for his original lawyers to examine - something they failed to do.
"Finally, it is a sad day because Mr Royal's murderers are still at large."
Mr Adams says he wants to rebuild his life after 14 years in prison
Earlier, Lord Justice Gage said a failure to use evidence relating to three topics which were available to the defence before the trial demonstrated that "the legal advisers at trial had failed".
He ruled: "It was this deficiency in pre-trial preparation which caused the failures which we have identified.
"It is difficult to conclude that the criticisms and failures which we have found in respect of any one of the individual topics were on their own sufficient to render the verdict unsafe but we are quite satisfied that taken together, cumulatively they were sufficient to render the verdict unsafe."
Claims that a member of the jury was biased against Mr Adams were rejected, however.
Mr Royal's shooting was said to have been a revenge killing for the fatal stabbing by Mr Royal of a man during a street fight in 1987.
Mr Royal had been cleared after two trials heard he had acted in self-defence against David Thompson, his son's 29-year-old former business partner.
Mr Adams was going out with the sister of Mr Thompson at the time and it was claimed he carried out the murder in revenge.
Newcastle Crown Court found Mr Adams guilty of Mr Royal's killing in 1993. His co-accused, John Hands, was acquitted.
Mr Adams had his case referred to the Court of Appeal by the Criminal Cases Review Commission, the independent body which investigates possible miscarriages of justice.