The investigation into Kevin Nunes' murder is to be reopened following an independent review.
Mr Nunes died in 2002 after he was shot in a 'gangland execution' in a Staffordshire village. He had been shot five times and was severely beaten.
Five men were convicted of the 20-year-old's murder in 2008, but their convictions were quashed four years later when the Court of Appeal ruled there had been a series of failings in the original investigation.
Last year, the Chief Constable of Staffordshire Police commissioned an independent review into the murder which happened in Pattingham.
It was undertaken by Merseyside Police, and following the end of that review the Chief Constable of Staffordshire Police, Gareth Morgan, said: "This is a significant moment for the family of Kevin and the wider public, but it is also a significant moment for Staffordshire Police.
"I have read in detail all the reports relating to the original investigation and the subsequent enquiries by the IPCC (now IOPC) and I’ve acknowledged the significant police failings that were highlighted, for which, on behalf of the Force, I have apologised.
"I am particularly sorry that the family of Kevin have not received justice for his death. I know they have been let down."
Mr Nunes was an expectant father and promising amateur footballer who was once on Tottenham Hotspur's books.