Updated

A man was convicted Thursday of poisoning and suffocating his wife, who left behind a letter implicating him should she come to an "early demise."

Mark Jensen, 48, was found guilty of first-degree murder in the death of his wife, Julie Jensen, and faces a mandatory life prison sentence, with the judge to determine if he should ever be eligible for parole.

Mark Jensen stared dourly at the jurors as each concurred with the judgment. Bailiffs led him quietly out the side of the courtroom afterward. Defense attorney Craig Albee left the courthouse without commenting.

Julie Jensen, 40, was found dead in her Pleasant Prairie home on Dec. 3, 1998, after being sick for a few days. Mark Jensen was charged with killing her in 2002, but legal wrangling over evidence repeatedly delayed the trial.

The evidence included a letter she wrote implicating her husband of 14 years should anything happen to her, as well as her statements to police, a neighbor and her son's teacher that she suspected her husband was trying to kill her.

"I pray that I am wrong and nothing happens, but I am suspicious of Mark's suspicious behaviors and fear for my early demise," Julie Jensen wrote in the letter. She told the neighbor to give it to police only if she died.

Julie Jensen's four brothers spoke at a news conference afterward, thanking the jurors, law enforcement agents and witnesses who testified against Mark Jensen.

"The witnesses had to endure hardship and muster a lot of courage to come forward," Michael Griffin said, adding that he hoped the case would give hope to other victims of domestic violence.

Jurors deliberated for about 32 hours over three days before reaching a verdict Thursday.

In closing arguments, attorneys on each side had said there wasn't enough evidence supporting the other's theory about the way Julie Jensen died.

Prosecutor Robert Jambois said Mark Jensen plotted to kill his wife, searching the Internet for information on ethylene glycol _ commonly used as antifreeze _ and then giving her sleeping pills and making her drink juice spiked with the toxic chemical.

When Julie Jensen's health appeared to improve, her husband pushed her face in a pillow and suffocated her, Jambois claimed.

Defense attorney Craig Albee said the prosecution's case relied on questionable witnesses _ jail inmates, a poison expert who made a crucial mistake and witnesses whose memories had faded after nearly a decade. Albee called experts to prove his claim that Julie Jensen was depressed and committed suicide.