This is the case that haunted a small town in Alabama for nearly two decades: two 17-year-old girls disappeared on their way to the birthday party and were later found by gunshot in the trunk of a car.
There was evidence that one of the girls had been sexually assaulted and the investigators collected DNA from the crime scene. The police chased hundreds of people over the years, but could not identify a suspect.
Until this month.
On Monday, the Ozark Police Department announced that, thanks to the same investigative technique that had led to an arrest in the Golden State Killer case, a suspect was in custody.
The suspect, 45-year-old Coley McCraney, was arrested on Friday and charged with aggravated murder and rape in the deaths of Tracie Hawlett and JB Beasley, found in Ms. Beasley's car along a highway on July 3, 1999. They had both been shot in the head.
It is at least the fourth case in five days that has been solved using genetic genealogy, the investigation technique being known. The arrest comes as attempts were made to develop and prohibit this method of identifying DNA left at the scene of the crime.
Hawlett's mother, Carol Roberts, told the Associated Press that she had become numb when she had heard that an arrest had taken place.
"He was not allowed to do that," Roberts said. "I just want to know why."
Police Department Chief Marlos Walker said that he had decided to try genetic genealogy soon after the high-profile announcement in April that Joseph James DeAngelo, a former police officer, had been indicted for crimes related to the notorious Golden State Killer.
"It made me aware of the case," he said in an interview.
The murder of the two teenagers was the obvious case to apply it, he said. A double murder is rare in Ozark, a town of about 15,000 located about 80 km south of Montgomery.
"This is the only case of its kind here," said Chief Walker. "It's the crime that shook everyone; not only our city, but even wider than that. This is one of the most important cases in Alabama. "
Chief Walker hired Parabon, a forensic science consulting firm specializing in genealogical genealogy, to assist him in this case. The first steps in identifying DNA in this manner are usually the same.
A genetic profile is loaded on GEDMatch, a genealogy database popular with family history researchers – and more recently, the forces of order. Then, the team of genealogists in genetics hopes a close match, ideally in the range of third cousins. In this case, the parents were more distant, said CeCe Moore, who heads Parabon's genetic genealogy team.
"When I first looked at this case, I did not think it would be an easy solution," said Moore. Nevertheless, his team was able to create a family tree, linking the closest matches to a common ancestor, and then completing the branches with a set of publicly available data.
In the end, it was a happy coincidence that changed the focus of the investigation. Although the Parabon team was not able to create a list of probable suspects, the family tree alluded to several possible family names. When Chief Walker consulted the list, one of them stood out: McCraney.
"I recognized that family name," he said, because he had a high school classmate with that last name. They graduated the same year and played basketball together.
There was a good chance that the McCraney, he knew, could be related to the suspect and that his DNA would help direct the construction of the family tree.
When the investigators compared his DNA to that of the crime scene, it seemed to fit perfectly, said Chief Walker.
"Like most people, I was surprised," said Chief Walker, stuck in his chair for three hours after hearing the news. Mr. McCraney had cooperated with the investigation and did not have the type of record or reputation that would allow him to suggest that he had been involved in this type of crime, Chief Walker said.
"But I've been doing it long enough to know that DNA is a solid thing to believe in," he said. "I had no reservations when we had a match that it was him."
Mr. McCraney has worked as a truck driver and preacher, according to the Associated Press.
David Harrison, McCraney's lawyer, told the Association that his client was an exceptional member of the community.
"I've been doing this work for a long time, and here's what worries me: social media condemns it before we've ever seen the evidence, which troubles me," he said.
The announcement of the Ozark Police comes after three other cases that were solved with the help of genetic genealogy last week, and more than 40 since April, according to Ms. Moore.
Questions about the legality of this new practice remain unresolved. In January, Maryland delegate Charles Sydnor introduced a bill that would prevent law enforcement agencies from identifying suspects' DNA by using relatives in genealogical databases. The bill died in a few weeks, but it fueled the debate as to whether this practice violated the privacy of individuals. Others worry about the excessive weight given to genetic evidence, when there are hundreds of reasons why a match does not necessarily constitute an indicator of guilt.
Advocates say that law enforcement agencies limit their searches to genealogy databases for which users have explicitly consented to participate in the investigation of killings and sexual assaults.
"It's a great tool," said Chief Walker. "I think more agencies will use it in the coming weeks and months."