DNA helps solve 1971 Pasco cold case. The killer died in prison for another murder

Advances in DNA technology have helped police finally link a man with a history of robbery, rape and murder to the 1971 killing of a 60-year-old woman inside of her Pasco home.

Detectives have long suspected Sam Pietro Evans brutally beat and choked Ivah McDonnell with her own pajama bottoms inside her home at 5008 W. Sylvester Street.

But now the Franklin County Sheriff’s Office was able to confirm that Evans, who died in Department of Corrections custody in 2016, was the man responsible for her murder.

McDonnell, who was single and lived alone, was found dead on Dec. 2, 1971 after two co-workers found her front door pried open, the telephone cord cut and the blankets pulled off of her bed, the Tri-City Herald reported at the time.

Evans was one of 14 suspects interviewed by police, but while detectives sent evidence to be tested by the FBI, state and private labs, they were never able to link him to the murder, Franklin County Sgt. Steve Warren said.

It wasn’t until 2023 when advances in finding DNA allowed the Washington State Patrol Crime Lab to identify Evans’ saliva on the pajama bottoms, Warren told the Tri-City Herald Friday.

Evans had a lengthy criminal history that included convictions for robbery in 1959, forgery in 1972, manslaughter in 1976 and armed sexual assault of a victim over age 65 in 1987.

He was arrested again in 2010 in connection with the 1972 killing of Jackson Schley.

Schley, 58, was shot during a robbery, and his wife Daisy, 46, was kidnapped and raped. She died in 2007, the Seattle Times reported in 2010.

He pleaded guilty to the killing and was still in prison for the crime when he died at the age of 77. He spent about 39 years in prison across multiple states, the Franklin County Sheriff’s Office said.

McDonnell had one extended family member left after 53 years, Warren said. The family member seemed relieved to finally have an answer to the death.

McDonnell’s Murder

Evans, who was 33 at the time of the killing, met McDonnell through a mutual friend and appeared to single her out.

While detectives collected a lot of evidence and suspected Evans, there was never enough evidence to charge him.

Former Benton County Coroner Rick Corson talked to the Tri-City Herald in 2010 about his experience with the case. Corson had just joined the Franklin County Sheriff’s Office in 1971.

“It was the only unsolved homicide for us during my time there,” Corson said in 2010. “Almost ever other year, somebody was assigned that case to try to find something new. We continuously worked that case. It was never left alone.”

Deputies never found the weapon used to break into McDonnell’s home or the one used to hit her, according to Herald archives. She had been knocked unconscious for about two hours before being strangled to death.

Then Sheriff Dick Boyles said robbery or rape was the likely motive to the murder, but the only things missing were her wallet, a jar full of change and some lingerie.

McDonnell’s friends described her as matronly, quiet and a bit of an introvert. Most of her activities were related to work. At the time, her closest relative was a cousin who lived in California, the Tri-City Herald reported.

When Evans’ name surfaced as a suspect in 2010, police tried to figure out exactly when he lived in the city in an attempt to connect him to the killings.

He was married to a Pasco woman until 1982, the Seattle Times reported.