DNA testing has helped to identity a teenage boy who was among four victims of a notorious serial killer to be buried in the 1980s at an abandoned farm in Indiana.

For nearly 40 years, the child has been known only as Adam Doe, one of many teenage boys and young men believed to have been murdered between 1982 and 1984 by Larry W. Eyler. Known as the "Highway Killer," Eyler was suspected of killing more than 20 people, most of whom were discovered near interstates in several Midwest states.

But four of Eyler's suspected victims were found in 1983 on an abandoned farm in rural Lake Village, Indiana. On Tuesday, Keith Lavell Bibbs, 17, of Chicago, was identified as the last remaining victim found on the farm, the DNA Doe Project and the Newton County Coroner's Office both announced.

"This significant breakthrough comes after years of exhaustive efforts, and it brings closure to a case that has puzzled investigators and haunted families for decades," Pam Lauritzen, a spokesperson for the nonprofit DNA Doe Project, said in a media release.

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News of the break in the decades-old case comes at a time when modern-day serial killers have once again captured the public's attention.

Just since May, several men have been arrested and charged in cities across the United States for killing sprees that gained national media coverage.

Police in Dallas, Texas arrested 25-year-old Oscar Sanchez Garcia last week in connection with the death of three women believed to be sex workers. Garcia was the latest suspect to be charged in a string of sex worker slayings after Rex Heurmann, a prominent architect in New York City, was also arrested last week in connection to the Gilgo Beach murders of Long Island.

In another Texas case, Raul Meza Jr., who was convicted in 1982 of the murder of an 8-year-old girl, was charged with two additional murders in May. Police believe Meza could be responsible for 10 more homicides, the Austin American-Statesman, part of the USA TODAY Network, reported.

Bryant Rivera, a California mann whom Mexican authorities have called the "Ted Bundy of Tijuana," was also charged earlier this month with femicide after he was accused of killing three women in Tijuana between September 2021 and February 2022. Rivera was arrested by U.S. officials as a fugitive from Mexico.

Genealogists traced through multiple generations before discovering Bibbs' identity

Eyler was convicted and sentenced to death by lethal injection for the 1984 kidnapping and murder of 16-year-old Daniel Bridges. During his time on death row, he later confessed to additional murders before he died in 1994 of an AIDS-related complication at 41 years old.

Many of his victims were hitchhikers and male prostitutes whom Eyler would offer alcohol and drugs before restraining and attacking them. Shortly before his death, Eyler confessed to numerous murders to his defense attorney, who released the recorded confession posthumously with her client's permission.

Among those identified to be among Eyler's victims were four males whose decomposing bodies investigators discovered in October 1983 alongside an oak tree close to an abandoned Indiana farmhouse in Newton County. The victims, who were only partially buried, had each been stabbed more than two-dozen times and were found with their pants around their ankles.

Two of the victims, Michael Bauer, 22, and John Bartlett, 19, were identified early in the investigation, while the other two became known as Adam and Brad Doe, Newton County Coroner Scott McCord said. Brad Doe was identified by the DNA Doe Project as John Brandenburg Jr. in 2021.

The DNA Doe Project became involved in identifying the two victims in 2020 when it said McCord's office sought the organization's help. The nonprofit organization helps to trace the genetic genealogy of unidentified victims at no cost to local governments with funding support from donations to cover lab costs and operational support.

Because Bibbs' DNA was "highly degraded," the case languished for more than two years in the labs as volunteer genealogists worked to create a DNA profile that could be uploaded to the databases used for forensic cases, Lauritzen said.

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Bibbs was the only one of the four victims found on the Indiana farm who was African-American, which posed a challenge to genealogists who said that Black people are underrepresented in the DNA databases. Researchers were required to work back multiple generations to find a common thread among DNA relatives, according to the DNA Doe Project.

It wasn't until January that McCord said the investigators finally started to get some traction when Bibb's potential brother's allowed for a DNA sample to be collected and tested. The sample was sent to the Indiana State Police Lab in Indianapolis for “kinship” testing, which proved conclusive that the deceased male was Bibbs, McCord said.

“We needed to stay focused, committed, and consistent in our work,” said DNA Doe Project team leader Elias Chan in a statement. “It was a complicated family structure involving many name changes. We were able to find a DNA cousin’s public family tree that helped point us in the right direction.”

Eric Lagatta covers breaking and trending news for USA TODAY. Reach him at [email protected] and follow him on Twitter @EricLagatta.