Detectives determined the shooter used a .22 caliber gun. In December 1974, Washington County Sheriff’s deputies arrested Steven Paul Criss, who they said was "a potential suspect shortly after the murders." Investigators reportedly found a .22 caliber gun in Criss' car, which was illegally concealed.
Ballistics evidence, however, could not link the gun in Criss' possession and the weapon used to kill Bartron and Zito. The case went cold.
Then, Criss joined the U.S. Army and was stationed at Fort Lewis in Washington. In 1976, he reportedly used his .22 caliber gun to shoot and kill his commanding officer, Sgt. Jacob "Kim" Brown in the head.
Criss pleaded guilty and was sentenced to 35 years in prison. He was released on parole in 1988.
Then in 2022, Washington County Sheriff’s Office detectives sent ballistic evidence to the Bureau of Alcohol, Tobacco, Firearms and Explosives, which came back with a "presumptive match" involving evidence from the 1974 murders of the teens and 1976 death of Sgt. Brown. According to the Sheriff’s Office, "To date, the ATF reported this is the oldest known comparison and match on a prosecutable case."
The Oregon State Police Crime Lab reportedly confirmed the match too.
Criss was indicted by a grand jury on two counts of second-degree murder in November. He is being held in the Washington County Jail.
The Washington County Sheriff’s Office also issued an apology to Joseph Amir Wilson and his family. Wilson was reportedly arrested and charged with Bartron and Zito’s murders "a few hours" after they were killed. Prosecutors dropped charges against him in January 1975, saying Wilson "was innocent and never should have been arrested."
Officials also believe Criss "was responsible for additional homicides."