The defense's assertion that a woman committed suicide to frame her husband is ridiculous and not plausible, a prosecutor told jurors in closing arguments Monday.

Prosecutor Robert Jambois said Mark Jensen gave his wife sleeping pills in the days before her 1998 death so he could give her multiple doses of ethylene glycol — the toxic chemical commonly used as antifreeze.

He used the sleeping pills "to make Julie Jensen more malleable, more susceptible to the poison he was putting in her system," Jambois said.

Jensen, 48, is charged with first-degree murder in the 1998 death of his 40-year-old wife. He faces a maximum penalty of life in prison without parole if convicted.

Jambois said there is no evidence to support a defense assertion that Julie Jensen committed suicide and framed her husband for murder, something that would have ensured their two children were left without parents.

"What evidence did you hear in this case that would support such an utterly ridiculous utterly, implausible presentation?" Jambois asked the jurors. "Did you hear any evidence that would suggest Julie Jensen was that kind of bitter, vindictive person?"

Julie Jensen also could not have gotten out of bed the day before she died to do Internet searches on the stages of ethylene glycol poisoning and again on the day she died to try to erase the searches, Jambois said. The searches were found on the family computer.

The defense planned to present closing arguments and case was expected to go to the jury later Monday.

Jensen was charged in 2002, but legal wrangling over evidence delayed the trial.

That evidence included a letter Julie Jensen wrote before she died pointing the finger at her husband. It also included her statements to police, to a neighbor and to 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 said in the letter that prosecutor Robert Jambois read during his opening statement.

Until recently, using such evidence in court was virtually unheard of because of constitutional guarantees giving criminal defendants the right to confront their accusers.

However, the Wisconsin Supreme Court created new evidence rules, guided by a U.S. Supreme Court decision that laid the groundwork for the use of Julie Jensen's letter and statements to police.

For years, authorities said Julie Jensen had died of multiple doses of ethylene glycol, commonly used as antifreeze. But a jail inmate, Aaron Dillard, came forward last year and said Jensen confessed to smothering his wife.

Dillard said Jensen told him that he put antifreeze in her juice and she got sick. But when Julie Jensen appeared to be getting better, he "rolled her over and sat on her back."

Jambois said Dillard is a con man with a criminal record as long as his arm, but that doesn't mean he is not credible.

"There is no way that Aaron Dillard could have anticipated that the physical evidence precisely corresponded to the description of the murder unless it was the murderer who told him that," Jambois said.