William George Bundy's younger sister remembers how more than three decades ago her teenage friends would come over to their Chicago home to flirt with the young man everybody called Bill. He was gregarious, an accomplished diver and gymnast at Senn High School who earned a thick wad of cash from working construction jobs after he dropped out.

Then one night in October 1976, the 19-year-old disappeared after he left home.

As the mystery lingered year after year, all his sister had left of him was the bracelet she had given him for his 18th birthday, a grade school autograph book, a patch for one of his jackets and a few other items. Their parents, who had divorced before his disappearance, were never the same.

The family had long nursed dark fears and grim suspicions: that Bill Bundy had been a victim of serial killer John Wayne Gacy.

On Tuesday, 35 years after he disappeared, the mystery was solved when Cook County Sheriff Tom Dart said authorities confirmed Bundy's remains through DNA as one of eight Gacy victims who had never been identified. It marked the first match in Dart's efforts to put names to all eight victims.

"I always knew he was going to be one of them," Bundy's sister, Laura O'Leary, of Chicago's Northwest Side, said at a news conference with Dart and other officials working on the renewed investigation of Gacy's victims. "But without DNA back then, there was nothing I could really do."

Indeed, the advance of science was what enabled the authorities to make the match. At the time of Bundy's disappearance, authorities relied on dental records and X-rays to identify skeletal victims.

In 1979, as investigators tried to identify Gacy victims after his arrest and the grisly discovery of 33 bodies, Bundy's mother sought her son's dental records but learned the dentist had retired. She finally found the dentist only to learn that he destroyed all of his records, according to the sheriff.

After learning of Dart's renewed efforts to identify Gacy's still-unknown victims, O'Leary logged on to her computer before dawn one morning and filled out a form for families who believe their loved ones were among those victims.

Later, she and her brother, Robert Bundy, provided DNA samples to sheriff's officials. Those samples were sent to a Texas university laboratory and compared with a DNA profile taken from the remains of Victim No. 19, the 19th body removed by authorities from the crawl space of Gacy's brick home. Those remains had recently been unearthed from Resurrection Cemetery in suburban Justice under a headstone that reads "We Remembered."

Linking Bundy to Gacy made sense for the family because Gacy was known to lure his victims with job offers at his remodeling and construction business. He urged youths to come to his home on West Summerdale Avenue in Norwood Park Township to sign work papers, then killed them. Dart said that, although detectives do not know for sure Gacy met Bundy in that way, it seems a logical conclusion.

"He said he'd pay $10 an hour, which was a lot back then," Dart said of Gacy.

Gacy was convicted of the murders of 33 young men and boys in the 1970s, all but one of them strangled, many of them recovered in the crawl space. He was executed by lethal injection at Stateville Correctional Center in Crest Hill in 1994 after his appeals failed.

Since October when Dart went public with the effort to identify the eight unknown Gacy victims, sheriff's detectives have received 125 leads of missing persons, 80 of which required more investigation. Many were eliminated by dates they went missing or some other variable that ruled them out, such as that Gacy already was behind bars when the person disappeared. Police have taken 11 DNA samples from eight different families.

DNA samples from four other families did not match any of the other unknown Gacy victims. Six DNA samples still are in the process of being tested for a match.

Dart said detectives have received inquiries from people in 29 states. They have also submitted Gacy's blood for DNA testing so his genetic profile could be entered into the national DNA database on the chance of a match to other crimes committed in the 1970s when Gacy was known to have traveled widely. But Dart called the chances of linking Gacy to other crimes "slim at best" because law enforcement in the 1970s did not save blood evidence as it does now routinely for DNA testing.

On the October night he went missing, Bundy told his family that he was going to a party. O'Leary, who was 15 at the time, said she remembered him leaving.

"That was the last time I saw him," she said at the news conference.

When Bundy did not return home, O'Leary said, the family reported him missing to police. But she said the family came to feel that his disappearance was "not handled aggressively" by the police, perhaps because Bundy was over 18 and free to leave if he wanted. The loss, she said, left her divorced parents to struggle emotionally.

Her mother died in 1990, she said, while her father died about five years ago.

"My mother, she was really never the same," said O'Leary. "She was pretty much in denial."

Flanked by Dart and other investigators, O'Leary said she has held on to a handful of her brother's belongings, including his high school identification card.

When O'Leary thinks of her brother, she said, she remembers the family Christmases and his popularity with her friends, who were younger than he was.

"All of my girlfriends wanted to date him," she said. "They weren't coming there for me."

The identification that he was a Gacy victim, she said, was a long time coming. It turns out that other members of the Bundy family are buried at Resurrection Cemetery. So O'Leary and others in her family have been coming to the cemetery for years to visit the graves of relatives who have passed on, not knowing her brother's remains were close by.

Come spring, she said, her brother's remains will be moved closer to the family plot.

"This is a terribly sad day for our family," she said, "but it's also a day that provides closure. …

"The sorrow will eventually go away. And now I'll have a place to visit him."

smmills@tribune.com

jmeisner@tribune.com