Wisconsin ? 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.

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.