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Wisconsin man again found guilty of killing wife with antifreeze at retrial

Mark Jensen had been serving a life sentence after being convicted of the murder 15 years ago. Then controversy over inadmissible evidence got his conviction overturned, spurring another trial.

KENOSHA, Wis. (CN) — For the second time in two decades, a Wisconsin man was found guilty of first-degree homicide on Wednesday for poisoning his wife with antifreeze, ending another chapter in the sprawling, bizarre murder case.

At around 1:30 p.m., the jury serving at the trial of Mark Jensen, 63, unanimously found him guilty after 15 days of testimony and less than one full day of deliberations.

Kenosha County Circuit Court Judge Anthony Milisauskas – the third Kenosha judge to preside over Jensen’s case – polled each of the 12 jurors for their verdict at the defense’s request, and they were unanimous. After his bond was revoked, Jensen was taken back into custody and quietly escorted out of the courtroom by sheriff’s deputies as members of the prosecution team hugged crying spectators from the gallery.

The court scheduled sentencing for April 14. Jensen faces life without parole, the same sentence he received the first time around.

The winding path to Jensen’s second conviction began in 2002, when Kenosha County prosecutors charged him with murdering his 40-year-old wife, Julie Jensen, in 1998. Then and now, prosecutors claimed he did so in part by surreptitiously feeding her antifreeze and suffocating her in her bed at the Pleasant Prairie home they shared with their two sons.

The state’s theory was that Jensen committed the murder because he was consumed by resentment of an affair his wife had in the early 1990s. The murder also allowed him to openly date a co-worker he was having an affair with and later married, prosecutors said. The two were later divorced and the co-worker, Kelly LaBonte, testified for the state at Jensen’s retrial.

After a lengthy initial trial presided over by two Kenosha judges and relocated to nearby Walworth County because of its high-profile nature, Jensen was convicted in 2008 of first-degree murder and sentenced to life without parole.

Numerous appeals and legal fights followed. Of particular focus was the inclusion at Jensen’s first trial of from-the-grave evidence in the form of a letter Julie Jensen wrote and gave to a neighbor implicating her husband as her murderer in the event of her death, as well as two voicemails she left with a now-deceased Pleasant Prairie police officer stating that Jensen should be the “first suspect” should she be found dead.

Jensen and his lawyers argued the evidence could not be admitted because it violated the accused’s Sixth Amendment right to confront his accuser. After the issue was handled by the Wisconsin Supreme Court and the U.S. Supreme Court issued rulings on related matters, the circuit court found, notwithstanding Jensen’s Sixth Amendment rights, the letter and voicemails were admissible under the doctrine of forfeiture by wrongdoing.

Jensen’s state court appeals subsequent to his conviction repeatedly failed, but a habeas corpus petition filed in Milwaukee federal court eventually prevailed. In 2013, U.S. District Judge William Griesbach found the Wisconsin Court of Appeals had wrongfully considered it harmless error to admit Julie Jensen’s from-the-grave statements in violation of his Sixth Amendment rights and vacated his conviction.

Prosecutors immediately sparked fresh proceedings against Jensen. The circuit court at first reinstated his conviction and sentence without a new trial, but Jensen again appealed and the issue worked its way back to the Wisconsin Supreme Court.

The state’s highest court ruled in 2021 that the law on testimonial hearsay had not changed to the extent that Jensen’s wife’s statements were admissible, blocking their inclusion as evidence. The U.S. Supreme Court declined to review the state supreme court’s ruling the following year, setting the stage for Jensen’s retrial, which began in January.

Robert Jambois, formerly an assistant Kenosha County district attorney who prosecuted Jensen’s first trial, reprised his role as the state’s lead attorney in the retrial, this time as a special prosecutor. Jensen was represented by a team of defense lawyers led by Jeremy Perri, who recently acted as Darrell Brooks’ counsel in the trial over the fatal tragedy at a 2021 Waukesha Christmas parade before Brooks dumped his defense team at the last minute and represented himself.

Perri and the other members of Jensen’s defense argued that Julie Jensen suffered from severe depression and died by suicide, framing her husband in the process. They further argued the state was too focused on the more salacious aspects of the case and engaging in confirmation bias.

The dozens of witnesses appearing for the state—with some video testimony dating from Jensen’s first trial and murder investigation, including from witnesses now deceased—featured current and former police, neighbors, friends, co-workers, experts in forensics and computers, and family of both Jensen and his wife. Jensen himself declined to testify.

Some testimony spoke to Jensen's sexual hang-ups, including one co-worker who testified about seeing notebooks belonging to Jensen full of sketches of penises. LaBonte testified about flirtatious emails between her and Jensen and the fact that he referred to his penis as “Boy Scout.”

Other testimony detailed pornography on Jensen’s computer and web activity and conversations in which he appeared to be interested in poisons like ethylene glycol – an ingredient in antifreeze – and how to get away with murder by making it look like suicide.

Still more testimony alleged a prolonged, anonymous campaign of harassing phone calls and emails Jensen carried out to terrorize his wife before killing her, including randomly placing pornography in and around their home in the years before her death.

Ultimately, the much disputed from-the-grave evidence was unnecessary for the jury to find Jensen guilty, said John Patrick Gross, a law professor at the University of Wisconsin. All the other scientific evidence, Gross added, was enough to make Jensen “the prime suspect.”

“He had a motive, the means to carry out the murder and absent some other plausible explanation as to how his wife was poisoned, it was hard to believe the jury would reach a different conclusion than they had in the first trial,” Gross said.

Jensen will remain at the Kenosha County Jail pending sentencing. He had since 2008 been housed at Dodge Correctional Institution in Waupun, where it is likely he will return to continue serving his life sentence.

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