Nearly 40 years after Harold and Thelma Swain were shot to death in a small church in Camden County, Ga., and after a man was wrongly sent to prison for two decades over the crime, the authorities arrested another man who they believe murdered the Swains.

The man, Erik Kristensen Sparre, 61, of Waynesville, Ga., was charged with two counts of murder and two counts of aggravated assault in the 1985 deaths of the Swains, the Georgia Bureau of Investigation announced on Monday.

Dennis Perry, who is now 62, was convicted of two counts of homicide in 2003 but he was released in 2020 after his conviction was overturned, in part because reporting by The Atlanta Journal-Constitution cast doubt on an alibi that Mr. Sparre had used when he was investigated after the killings.

Mr. Sparre was arrested in Waynesville, about 90 miles south of Savannah, at a store near his home without incident, according to the Bureau of Investigation. He was booked into the Camden County Jail. The Bureau of Investigation declined to comment further.

After a Bible study session in 1985, Harold Swain, 66, and Thelma Swain, 63, a married couple, were killed in the vestibule of the Rising Daughter Baptist Church in Waverly, Ga., about 14 miles southeast of Waynesville.

Investigators contacted Mr. Perry after receiving a tip, learned that he had been working hundreds of miles away in the Atlanta area around the time of the killings, and cleared him.

Mr. Sparre was a person of interest early in the investigation but he was dismissed after a person purporting to be his boss told the authorities that Mr. Sparre was at work at the time of the killings, according to The Atlanta Journal-Constitution, which reported that it could not verify the supervisor’s identity.

The case went unsolved until 2003 when Mr. Perry was convicted of the murders in large part because a woman testified that she had heard Mr. Perry say that he was going to kill Harold Swain. Crucially, Mr. Perry’s lawyers said that the jury that convicted Mr. Perry of two counts of homicide was not told that the woman had received $12,000 in reward money.

The case against Mr. Perry was subject to scrutiny over the years as advocates questioned whether there was enough evidence to convict him. Some strands of hair attached to glasses that were left at the crime scene did not match Mr. Perry’s DNA.

But the case was not reopened until May 2020. The Atlanta Journal-Constitution published an award-winning investigation called “An Imperfect Alibi” that questioned whether Mr. Sparre’s boss had really verified Mr. Sparre’s attendance at work on the night of the killings. The reporting compelled the Georgia Innocence Project to get a hair sample from Mr. Sparre’s mother to see if she was related to the person whose DNA was left at the crime scene. It was a match.

Attempts to reach Mr. Sparre and two family members were not successful. No lawyer was listed for Mr. Sparre.

Mr. Sparre had previously told The Atlanta Journal-Constitution that he is innocent.

Mr. Perry could not be reached for comment.

“I never gave up hope,” Mr. Perry said in a previous comment. “I’ve always been innocent, and that’s what I tried to tell them. People don’t want to listen.”