A genetic genealogy investigation led to a breakthrough in the 1972 case of a teenage girl who was stabbed to death and dumped in a cornfield.
Barry Lee Whelpley, 76, was arrested last week at his home in Minnesota for the killing of 15-year-old Julie Ann Hanson in Illinois almost 50 years ago.
Officials say that they identified the suspect using genetic genealogy, which allegedly tied his DNA to the crime scene.
The investigation technique allows officers to search for family members who have voluntarily submitted their own DNA to popular ancestry databases.
It was most famously used to capture “Golden State Killer” Joseph DeAngelo for a string of rapes and murders, which he carried out between 1973 and 1986.
Authorities have refused to say which database was used in the arrest of Mr Whelpley, but police in the Chicago suburb of Naperville say they used the services of Identifinders International.
The California-based firm describes itself on its website as “worldwide cold case experts” and was founded by forensic genealogist, Colleen Fitzpatrick.
Julie Ann Hanson went missing after borrowing her brother’s bike to attend his 7 July 1972 baseball game.
She never returned home and after she was reported missing the next day her body was discovered in a field and she had been raped and stabbed 36 times.
Mr Whelpley, who was 27, at the time, was living a mile from her family’s home when she disappeared.
He has been charged by the Will County State’s Attorney’s Office with three counts of First-Degree Murder.
The retired welder, who has two daughters, is being held on $10m bail in a Minnesota county jail pending his extradition to Illinois.
“This brutal crime haunted our community for many, many, many years,” said Naperville Police Chief Robert Marshall.
“This was never a cold case … we continually investigated.”
Julie’s parents are now dead but remaining family members thanks the police for their efforts.
“As you might assume, it has been a long journey for our family,” they said in a statement.
“We are forever grateful to all those who have worked on this case throughout the many years.”