© Ethan Hyman/Raleigh News & Observer/TNS In this February 28, 2013 photo, Joseph Sledge poses at Pamlico Correctional Institution in Bayboro, North Carolina, February 28, 2013. WHITEVILLE, N.C. (AP) — A 70-year-old man was wrongly convicted in the stabbing deaths of a mother and daughter nearly four decades ago and should be freed from prison, a three-judge panel ruled Friday.

The judges heard from a DNA expert who said none of the evidence collected in the case matched Joseph Sledge. A district attorney apologized to Sledge and promised to reopen the case into the 1976 slayings.

"The system has made a mistake," district attorney Jon David said. "The wrong man is in prison."

After the judges' decision was announced, Sledge was still for a moment, then hugged his lawyer and family members who attended the hearing.

Sledge was being processed for release, which was likely to happen Friday afternoon. His nephew Maurice Sledge said the family planned to take him to Savannah, Georgia, to live with one of Joseph Sledge's brothers.

Sledge was convicted of two counts of second-degree murder and sentenced to life in prison in the September 1976 slayings of Josephine Davis and her daughter, Aileen. They were found stabbed to death in their home in Elizabethtown, a day after Sledge had escaped from a prison work farm where he was serving a four-year sentence for larceny.

Sledge is the eighth person exonerated after the state set up the North Carolina Innocence Inquiry Commission, the only state-run investigative agency of its kind. The commission found there was enough doubt to review Sledge's case, and the state Supreme Court appointed the three judges to hear it.

In addition to fingerprints, DNA and hair gathered at the scene that didn't belong to Sledge, a key jailhouse informant, Herman Baker, signed an affidavit in 2013 recanting trial testimony. Baker said he lied at the 1978 trial after being promised leniency in his own drug case and he said he'd been coached by authorities on what to say.

The commission began operation in 2007. It has completed reviews of about 1,500 cases.

The nonprofit Innocence Project said there have been 325 post-conviction DNA exonerations in the U.S.