A three-judge panel on Friday declared a North Carolina man innocent after he had served almost 40 years of a life sentence for a 1976 double murder.

Now 70 years old, Joseph Sledge walked out of jail a free man on Friday, thanks in part to DNA evidence.

He received an apology from the local district attorney, who vowed to reopen the case of the stabbing deaths of Josephine and Aileen Davis in Elizabethtown, North Carolina, and find the real killer, according to local media reports.

North Carolina is one of 29 states that provides compensation for the wrongfully convicted at a rate of $50,000 for each year of wrongful incarceration, according to the New York-based Innocence Project. However, the maximum amount an exoneree can seek is $750,000.

Compensation for the wrongfully convicted varies greatly throughout the nation and there are still more than 20 states that offer nothing at all.

Sledge became a suspect in the stabbing deaths because his escape from a nearby prison coincided with the murders, reported Reuters. He did not have a history of violence and had been serving time in prison for theft.

He was convicted of double murder in 1978 by a jury.

While Sledge maintained his innocence as the decades passed in prison, his day of freedom almost didn’t come.

In 2004, attorney Christine Mumma of the North Carolina Center on Actual Innocence (NCCAI) took his case, but, in 2012, after exhausting what seemed to be every option, she considered closing the case, reported the Associated Press.

That was when an envelope containing hairs believed to belong to the killer, was discovered by court clerks hiding high on a shelf. Forensic testing would reveal that the hairs did not belong to Sledge.

Sledge’s exoneration is the eighth in a series of case reviews done by the North Carolina Innocence Inquiry Commission.

In September 2014, the U.S Attorney’s office established the first federal unit dedicated to investigating wrongful convictions.