CHICAGO (AP) — A North Carolina man who moved to Chicago was one of the victims of John Wayne Gacy, who was convicted of killing 33 young men and boys in the 1970s, authorities said Monday.

Francis Wayne Alexander would have been 21 or 22 years old when Gacy killed him sometime between early 1976 and early 1977, Cook County Sheriff Tom Dart said at a news conference announcing the identification of Alexander’s remains.

In a statement, Alexander’s sister, Carolyn Sanders, thanked the sheriff’s office for giving the family some level of “closure.”

“It is hard, even 45 years later, to know the fate of our beloved Wayne,” Sanders wrote. “He was killed at the hands of a vile and evil man. Our hearts are heavy, and our sympathies go out to the other victims’ families. … We can now lay to rest what happened and move forward by honoring Wayne.”

Alexander’s remains were among 26 sets that police found in the crawl space under Gacy’s home just outside the city. Three victims, meanwhile, were found buried on Gacy’s property and four others whom Gacy admitted killing were found in waterways south of Chicago.

In 2011, Dart’s office exhumed the remains of eight victims, including Alexander, who had been buried without police knowing who they were. Dart called on anyone who had a male relative disappear in the Chicago area in the 1970s to submit DNA. That was the time when Gacy was luring young men and boys to his home to eventually kill them.

Within weeks, the sheriff’s office announced that it had identified one set of remains as those of William Bundy, a 19-year-old construction worker.

In 2017, the office identified a second set as those of 16-year-old Jimmy Haakenson, who disappeared after he phoned his mother in Minnesota and told her that he was in Chicago.

The details of Alexander’s life in Chicago are sketchy. Born in North Carolina, he moved to New York and then on to Chicago, where he was married for approximately three months before he was divorced in 1975.

According to the sheriff’s office’s news release, the last known record of Alexander’s life was a traffic ticket he received in Chicago in January of 1976 — a year in which he earned little money. How he crossed paths with one of the most notorious serial killers in American history is a mystery, as authorities say all they know is that “Alexander lived in an area that was frequented by Gacy and where other identified victims had previously lived.”

The identification of Alexander came together when the sheriff’s department teamed up with a nonprofit called the DNA Doe Project, which uses genetic information to locate relatives of dead people who have not been identified. The organization compared the DNA profile from the unidentified victim’s remains to profiles on a genealogy website to find potential relatives. That led it to Alexander’s family, and Alexander’s mother and half-brother provided their DNA for comparison.

Between the genetic testing, financial records, post-mortem reports and other information, investigators were able to confirm that the remains were Alexander’s.

The submission of DNA from people who suspected Gacy might have killed their loved ones has helped police solve at least 11 cold cases of homicides that had nothing to do with Gacy, who was executed in 1994. It has also helped families find loved ones who, while missing, were alive, including a man in Oregon who had no idea his family was looking for him.