Yellowstone County Sheriff Solves 1978 Billings Homicide of Corina Contreraz

For 47 years, the family of 16-year-old Corina Lydia Contreraz lived with an unanswered question: who killed her? Now, Yellowstone County investigators say they have identified the man responsible for the 1978 murder that left a family and community searching for answers for nearly five decades.

Corina’s life was cut short on December 22, 1978. A school bus driver making early morning rounds discovered her body near the intersection of Pryor Creek Road and Indian Creek Road, just east of Billings, according to reporting on the case.

An autopsy revealed that Corina had been sexually assaulted and stabbed 18 times. Despite immediate efforts by law enforcement, no suspects were arrested at the time, leaving her family and neighbors with decades of painful uncertainty.

How 1982 Fingerprint DNA Evidence Solved the Corina Contreraz Murder

Yellowstone County Sheriff’s investigators have identified Angelo James Stallsmith Sr. as the person responsible for Corina’s death. Stallsmith was believed to have been 29 years old when the crime occurred.

The long-awaited breakthrough came through advances in forensic genealogy. Detectives extracted viable DNA from a 1982 booking fingerprint card connected to Stallsmith. That genetic profile helped investigators identify him in the 1978 cold case.

Stallsmith died at Billings Deaconess Hospital in 1990 at age 41. Investigators say there is no indication that Stallsmith and Corina knew each other, and the weapon used in the attack was never recovered.

Billings Cold Case Brings Long Wait for Answers

Corina's death remained a deeply felt loss in the Billings area for generations. For years, her case was discussed alongside another local tragedy: the unsolved 1978 homicide of 21-year-old Marsha Helgeson, whose body was found months earlier outside Billings.

Investigators previously explored a possible connection between the two deaths, as detailed in a 2022 examination of the two cases. Identifying Stallsmith brings a long-overdue resolution to Corina’s case.

For her surviving loved ones, the announcement brings a complicated mix of grief and relief. Corina’s cousin, Dotty Ramirez, said she was grateful to still be alive to know that Corina’s case had finally been solved.