'He's been held accountable:' Jury finds John Bayerl guilty in 1979 murder of his wife in Muskego

John Bayerl

WAUKESHA COUNTY -- The jury reached a guilty verdict Wednesday, June 26 in the case of John Bayerl, charged with first degree murder in the 1979 cold case murder of his wife, Dona Bayerl, 38, who disappeared from her Muskego home and was never found. The verdict was unanimous, after more than five hours of deliberations.

John Bayerl remained stoic when the guilty verdict was read aloud. In fact, he never showed emotion during the trial, with the evidence far from clean-cut. Because Dona Bayerl's body was never found, and DNA testing wasn't available back then, the prosecution relied on circumstantial evidence. The district attorney argued John Bayerl had a history of being abusive and kept changing his story about the night Dona Bayerl disappeared. The defense argued that wasn't enough to prove beyond a reasonable doubt that John Bayerl killed his wife.

In the end, a detective with the Muskego Police Department who took over the case in 2012 said time and a fresh set of eyes were key to finally getting justice for Dona Bayerl.

"We worked on this case as a matter of over 40 years. You can't look at it the same as other people. You have to change your thinking. You have to look at it from a standpoint of eliminating other plausible, commonsense realities, and I believe we did that here today," said Stephen Westphal.

"Obviously, there's still questions that the family has answers to. We weren't able to provide those answers to the course of the trial, and so it's a bittersweet thing, but we're very, very pleased that after all these years, he's been held accountable," said Sue Opper, Waukesha County district attorney.

Westphal said the search would continue for Dona Bayerl's body -- and they would continue to seek answers as to what happened on May 6, 1979.

Sentencing was set for Aug. 30.

John Bayerl, Dona Bayerl

Closing arguments took place on Wednesday. Tuesday was the final day of testimony.

John Bayerl declined to take the stand, and the defense declined to present any of its own evidence, closing the testimony portion of the trial on Tuesday.

The final witnesses for the prosecution focused on the forensic evidence and John Bayerl's statements to law enforcement.

In the days and weeks following the disappearance of Dona Bayerl, members of the Muskego Police Department recalled John Bayerl's behavior when he learned blood spatter was discovered in the couple's garage.

John Bayerl, Dona Bayerl

John Johnson

"He had a white T-shirt on, and the area of his heart started moving when we told him about the blood stains," said John Johnson, former lieutenant.

While DNA testing wasn't available four decades ago, possible blood recovered on a bottle from the Bayerl home was re-tested in 2018, and matched Dona Bayerl's DNA profile.

"Is there any way to confirm that the DNA profile is a blood DNA profile?" asked the defense.

"There's no way to confirm that," said Ronald Witucki with the Milwaukee Crime Lab.

Ronald Witucki

Stephen Westphal

John Bayerl maintained over the years Dona Bayerl stormed out of the house the night she went missing after they got into an argument. She was never found, but a current Muskego detective said the mother of two was presumed dead based on her missing person's report in the national law enforcement database NCIC.

"In the 40 years Dona Mae has been listed in NCIC, has there been any hits in NCIC?" asked the district attorney.

"No," said Detective Stephen Westphal.

Westphal testified that he re-interviewed John Bayerl in 2018.

"He also thinks she's dead?" asked the district attorney.

"Yes," said Westphal.

Dona Bayerl and children

Westphal said the 79-year-old who has difficulty hearing slammed his fist while they talked about his past relationships with women.

"Do you think John Bayerl killed Dona Bayerl?" asked the district attorney.

"Yes," said Westphal.