An Atlanta Journal-Constitution documentary will air on Georgia Public Broadcasting, detailing the newspaper’s reporting that helped free a man from prison after he served 20 years for a crime he insists he didn’t commit.

“The Imperfect Alibi” debuts at 8 p.m. on Oct. 6.

The film covers the murders of Harold and Thelma Swain, a beloved couple who were gunned down inside their South Georgia church in 1985 by a man who stopped by and asked to speak with the husband. Investigators with the Camden County Sheriff’s Office and the GBI worked for years to find out who the killer was, but the case went cold until 2000.

Dennis Perry, a construction worker who had previously lived near the church, was accused by his ex-girlfriend’s emotionally troubled mother of plotting to kill Harold Swain. A jury convicted Perry of two counts of murder in 2003.

This summer, the AJC’s reporting cast doubt on case against Perry. The newspaper looked into Erik Sparre, who had been a suspect in 1986 after his ex-wife’s family recorded him bragging about killing the couple, referring to them by a racist slur. Sparre, who has told the AJC he is innocent, is white; the Swains were Black.

Sparre was dropped as a suspect because he had an alibi, but the newspaper’s reporting showed that the alibi couldn’t have been true.

After learning of the alibi issues, Perry’s attorneys at the Georgia Innocence Project and the King & Spalding law firm decided to conduct a DNA test on the lone DNA evidence in the case: a couple hairs located in the hinge of a pair of glasses found inches from the bodies.

The test showed that someone in Sparre’s maternal line contributed the hairs. Sparre is the only person in his maternal line who, according to police records, told multiple people he committed the murders.

The GBI has re-opened the 35-year-old murder case and is investigating Sparre.

Brunswick Judicial Circuit District Attorney Jackie Johnson’s office fought to keep Perry in prison and failed. A judge overturned his convictions and Perry walked free in July.

The DA’s office has still not dropped the case against Perry, meaning he could be tried again, though legal experts have said a new trial of Perry would be outrageous because of the evidence against Sparre.

Perry is hopeful that he will be fully exonerated soon. In the meantime, he is thankful for small things that feel big after decades of imprisonment.

“I enjoy being home," Perry says in the documentary, “just being able to go outside when I want to, being able to get up when I want to.”