Mr Cole spurned an offer of early parole as it would have meant accepting guilt.
Years after his death, his family demanded DNA tests after they received a letter from a convicted rapist confessing to the crime.
It transpired the man had confessed earlier. He had sent letters to court officials four years before Mr Cole died - but the admission was never followed up.
Mr Perry said he hoped it would give Mr Cole's family a measure of peace.
Mr Cole's mother told the BBC she was ecstatic on hearing the news - as her son had always wanted to be exonerated.
He had written in a letter that he always believed in the justice system, even if the justice system had not believed in him.
This page is best viewed in an up-to-date web browser with style sheets (CSS) enabled. While you will be able to view the content of this page in your current browser, you will not be able to get the full visual experience. Please consider upgrading your browser software or enabling style sheets (CSS) if you are able to do so.
Bookmark with:
What are these?