BILLINGS, Mont. — A decades-old cold case has finally been solved as investigators have identified the man responsible for the 1978 murder of 16-year-old Corina Lydia Contreraz.
Contreraz was murdered on Dec. 22, 1978. Her body was found by a school bus driver at the intersection of Pryor Creek Road and Indian Creek Road east of Billings.
Watch the full story of Corina Lydia Contreraz's death below:
An autopsy conducted that same day revealed she had been sexually assaulted and stabbed 18 times.
No arrests were made at the time, and the case went unsolved for 47 years — until advances in forensic genealogy and DNA testing cracked it open.
Investigators identified the killer as Angelo James Stallsmith Sr., who was believed to be 29 years old at the time of the murder. Stallsmith later died in 1990 at Billings Deaconess Hospital (41).
According to the Yellowstone County Sheriff's Office, there is no evidence that Corina and Angelo knew each other or had previously met.
YSCO says no murder weapon was or has been located.
One critical piece of evidence helped break the case: a booking fingerprint card from 1982.
"We know he touched it, even though the card I worked on was from 1982, so even that many years later that DNA was still present," an investigator said.
Authorities say the case may never have been solved without modern technology.
"Without taking advantage of modern trends technology, we'd still be sitting there spinning our wheels," an investigator said.
For Contreraz's cousin, Dotty Ramirez, who traveled from Ohio, the news brings both grief and relief. Her last memory of Corina was tied to a birthday celebration — a moment she never imagined would be their last together.
"The next day we was shopping for a refrigerator for my mother. And when I came home, everybody was like looking at me like weird. And gave me a card from the detective and told me what happened. And I was like, petrified," Ramirez said.
The pain of losing Corina never faded over the decades.
"Her birthdays, pictures, just speaking with the family, it never went away. It was too awful to let go away," Ramirez said. "That's what hurts the most and nobody was there to help her."
While the family cannot recover the years lost, Ramirez says finally knowing the truth brings a measure of peace.
"I am like in awe. So grateful to God. That I'm still alive to be able to know that it's done," Ramirez said.
