WHITEVILLE, N.C. — A 70-year-old man wrongly convicted of the 1976 stabbing deaths of a mother and daughter walked out of prison Friday, saying he was looking forward to sleeping in a real bed and maybe swimming in a pool.

After serving nearly four decades behind bars, Joseph Sledge was found innocent by a three-judge panel who heard testimony from a DNA expert. The expert said none of the evidence collected in the case — hair, DNA and fingerprints — belonged to Sledge.

A key jailhouse informant had also recanted his story, saying authorities promised him leniency in his own case for his trial testimony against Sledge.

A district attorney who was not originally involved apologized to Sledge and promised to reopen the investigation.

“The system has made a mistake,” district attorney Jon David said.

After the judges’ decision was announced, Sledge was still for a moment, then hugged his lawyer and family members. Soon after, he walked out of the Columbus County Detention Center, spoke to reporters and got in a car with family members. They were headed to Savannah, Georgia, where Sledge was set to live with one of his brothers.

Asked what he was looking forward to doing, he replied: “Going home. Relaxing. Sleeping in a real bed. Probably get in a pool of water and swim.”

Sledge was convicted of two counts of second-degree murder and sentenced to life in prison in the September 1976 slayings of 74-year-old Josephine Davis and her 57-year-old 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 have the final say.

The 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.