Sam Hallam had his murder conviction quashed based on evidence which had lain on his mobile phone for seven years - proving he was at his grandmother's on the day of the killing.
Outside court, Paul May, who had led the campaign for his release which was backed by actor Ray Winstone, read a statement on his behalf.
In it Mr Hallam thanked everyone who had supported him and said: "I don't want anyone else to have to suffer what I have had to suffer since October 2004."
He added: "The identification evidence against me was so unreliable it should never have got to court and the prosecution should have disclosed all the relevant evidence to my defence team which they didn't.
"I now need time to recover with my family and I hope no-one ever suffers what I have had to for the last seven and a half years. Justice has long been denied to me, but has now prevailed."