Roy Beaulieu, convicted of second-degree murder, did not take the stand in his own defense.
Prosecutors cited a pathologist’s autopsy report as showing 63-year-old Laura Bruce was strangled on May 22, 1976.
But defense lawyer Robert Ferg argued that medical evidence showed the damage to Bruce’s neck was consistent with the 350-pound man’s account of accidentally falling on her after he had been drinking.
Bruce’s body was found alongside railroad tracks near Ladysmith.
The charge was filed after the body was exhumed in 2006 for forensic testing. The victim’s family had asked in 2005 for the case to be re-examined.
The jury of eight men and four women deliberated about three hours after hearing three days of testimony in Rusk County Circuit Court.
During the trial, Dr. Michael Stier, a forensic pathologist at the State Crime Laboratory in Madison, testified Bruce died from “homicidal strangulation” caused by compression on her chest and pressure on her neck.
When Bruce died, her tongue was sticking out, and strangulation was the most likely of three scenarios in which that happens, he said.
Beaulieu, a bachelor who lived with his mother until her death, told investigators he and Bruce went to a secluded area along some railroad tracks for sex and then argued, according to the criminal complaint. He told investigators he slipped on gravel, fell and struck Bruce in the chin and neck with his arm.
The maximum punishment for second-degree murder is 25 years in prison.
Beaulieu worked as a janitor at a now-defunct college in Ladysmith for 27 years. He had never been charged with a crime until he was accused of killing Bruce.

