Redwood City, Calif. ? Calling him “the worst kind of monster” and undeserving of sympathy, a prosecutor urged jurors to sentence Scott Peterson to death for murdering his pregnant wife before the panel began deciding his punishment Thursday.

“This is somebody who had everything and threw it away,” prosecutor Dave Harris said, pointing at Peterson as the convicted murderer sat stiffly at the defense table and intently watched the jury. “He had a plan and he executed it.”

In his 40-minute closing argument, Harris also reminded jurors that Thursday marked the two-year anniversary of Peterson’s “monstrous plan” to murder his wife, Laci.

“Two years ago today, the defendant, Scott Peterson, bought a boat,” Harris said. “He told (his mistress) Amber Frey his wife was ‘lost.”‘

But defense lawyer Pat Harris begged jurors to give Peterson the chance to “do some good for the rest of his life,” by sending him to prison instead of death row.

“I wish there was a phrase that I could give you that could turn this around and make you believe there is good, there is real, real good in this person,” he said. “But I don’t have that phrase … that’s up to you to decide.

“So I’m going to ask you … I’m going to beg you, begging you to go back there and please spare his life,” he added.

In his closing arguments, defense lawyer Mark Geragos told jurors he’d been “tormented” by the Peterson case — and surprised by the guilty verdicts.

“You can’t find a more tortured, emotionally charged case than when something like this happens to, what I consider to be, two very fine families,” he said.

Peterson, 32, was convicted Nov. 12 of one count of first-degree murder in the death of his wife and one count of second-degree murder for killing her fetus. The jury now has two options in deciding Peterson’s fate: death or life in prison without parole.

The jury deliberated Peterson’s fate for about two hours before retiring to an area hotel, where they will be sequestered until they decide whether to recommend a death sentence or life without parole. Deliberations are to resume this morning.

Prosecutors say Peterson killed Laci in their Modesto home on or around Dec. 24, 2002, then dumped her body into San Francisco Bay. The remains of Laci and the fetus were discovered about four months later a few miles from where Peterson claims to have been fishing alone the day his wife vanished.