Humberside Police say the case is closed and have declined to comment.
It's nearly 20 years since Lyndon Coles was jailed for the murder of Shane George in Hull.
In January 1994 Mr George answered the door at his home, and was gunned down. Within weeks Lyndon Coles and another man, Robert Bradley, were arrested.
The Humberside Police case said they killed the 21-year-old, a known drug dealer, in a row over drugs or stolen goods. They said he'd confessed to friends.
But still Coles denies he had anything to do with it.
"I've served a sentence, it wouldn't make any difference to me whatsoever, I've served the sentence now", he told Calendar in an exclusive interview.