(West Linn, OR) -- A 46-year-old cold case homicide in West Linn has been solved. Twenty-year-old Diana Kuhn was killed in 1978. Detectives had a person of interest, but didn't have the evidence. A detective reviewed the case and found a critical piece of evidence that had not been tested. DNA testing confirmed the person of interest, David Atkeson, was the suspect in the homicide. Atkeson died in 1989. The District Attorney says he believes, based on the evidence, Atkeson would have been convicted of sexual assault and aggravated murder.