Jury finds 79-year-old man guilty of wife's murder in 40-year-old Muskego case

WAUKESHA (CBS 58) -- A jury has found John Bayerl, 79, guilty of first-degree murder in connection with a 40-year-old Muskego cold case. 

"We are looking for closure, we are still looking for closure this just proves to you that the women and men of the Waukesha County District Attorney's Office and the Muskego Police Department past and present, we don't quit," Stephen Westphal, Muskego Police Detective.

John Bayerl, 79, is convicted of killing his wife Dona Mae. According to Bayerl, she stormed out of their Muskego home on May 6, 1979, after they had an argument and she was never seen again.  

To this day, investigators have not found her body. During the trial, the prosecution presented circumstantial evidence like testimony from John's two ex-wives who say he was violent during their marriages. Prosecutors also discussed the spots of blood found inside the Bayerl garage that matched parts of Dona Mae's DNA.

The defense argued that they do not know when the blood was transferred onto the Bon Ton bottle found in the garage. Despite the testimony and circumstantial evidence, the defense said there are no facts to prove John had the intent to kill. 

But after five hours of deliberation, the jury found Bayerl guilty of murder. He will be sentenced on August 30.