UPDATED 08/01/12 – 7:53 p.m.

CHICAGO (CBS) — The second day of the Drew Peterson murder trial was cut short on Wednesday, when a witness testified about finding a bullet in his driveway — believing Peterson planted it there to intimidate him — and defense attorneys promptly sought a mistrial.

The defense team objected to Thomas Pontarelli’s testimony on the subject, and prosecutors acknowledged they cannot prove any link between Peterson and the bullet.

Judge Edward Burmila called the line of questioning “a low blow that should not be presented.”

After discussing the matter behind closed doors with both sides, the judge offered the defense team the option of striking all of Pontarelli’s testimony entirely.

Defense attorneys asked to take the rest of the day to consider whether they want Pontarelli’s testimony stricken, or if they want to seek a mistrial, and the judge adjourned the trial until 9 a.m. Thursday.

LISTEN: WBBM Newsradio’s Mike Krauser reports

CBS2 Legal analyst Irv Miller said he was stunned by the prosecution’s lapse. “I couldn’t believe that experienced prosecutors would try to get in this type of evidence, where they clearly knew or should have known that they were wrong.”

Miller suggested that it might have happened because of desperation about the lack of evidence in their case against Peterson.

“I believe they know their case is weak,” Miller said, “and are trying to do whatever they can to salvage some kind of victory, to at least keep this jury out for more than 45 minutes. That’s what they’re really worried about.”

The judge said he is reluctant to declare a mistrial, and trusts jurors would be able to ignore Pontarelli’s testimony altogether, but wanted defense attorneys to determine if striking all of Pontarelli’s testimony would hurt their case.

Peterson is accused of killing his third wife, Kathleen Savio, in her bathtub in 2004.

Pontarelli, Savio’s neighbor, had been testifying that Peterson had told him not to help his ex-wife change the locks on her home. When prosecutors asked if Pontarelli felt intimidated, he said yes.

“He accused me of changing the locks. I said I didn’t, but I said I got his message yesterday. He said, ‘What was that?’ I said, ‘I found a .38-caliber bullet on my driveway.'”

That prompted an immediate objection from the defense team, and Burmila immediately sent the jury out of the room.

A furious Burmila then grilled prosecutor Kathleen Patton about why she allowed the witness to mention the bullet and leave the impression Peterson may have put it there.

When prosecutors acknowledged they could not prove Peterson put the bullet in Pontarelli’s driveway, an angry Burmila asked why they would let the jury think Peterson put it there if they couldn’t prove it.

But defense attorneys said the prosecution was intentionally trying to introduce evidence that would prejudice the jury against their client, even though it has been barred or is otherwise inadmissible.

Defense attorneys also argued the prosecution should be barred from retrying Peterson for Savio’s death, saying they shouldn’t benefit from inciting a mistrial.

It was the second time in as many days that Peterson’s attorneys requested a mistrial.

The fist time was during opening statements, when Will County State’s Attorney James Glasgow began to discuss an allegation that Peterson once tried to hire a hit-man.

Glasgow told jurors that a former co-worker of Peterson’s had said Peterson offered him $25,000 to find a hitman to kill Savio. The judge ruled prosecutors could not use testimony from that man.

Pontarelli was among those who found Savio’s body in her bathtub on March 1, 2004.

Pontarelli said that he stayed with Peterson after they found Savio’s body, and he overheard a phone call Peterson made, in which he said, “he just found his wife’s body in the bathtub and people are going to think he did it.”

While the initial autopsy said Savio died in an accidental drowning, Pontarelli testified that the bathtub did not look like it had been used.

“It was clean, pristine. There was no ring around the tub, no soap scum,” Pontarelli said. “Where were her clothes that she had on? Where were her clothes that she was going to put on? Where was her towel to step on?”

A second autopsy years later ruled Savio’s death was a homicide.

Pontarelli also testified, before Savio died, he helped her move some of her belongings out of Peterson’s home, and stored them in his garage. Peterson was not pleased, and told him, “Any friend of hers, is an enemy of mine,” Pontarelli said.

Pontarelli also testified that he installed a deadbolt lock on Savio’s bedroom door after Peterson moved out of the home he and Savio had shared.

During opening statements, Glasgow said Peterson twice got into the house and threatened Savio before she was found dead. The implication of Pontarelli’s testimony was that the deadbolt was needed because Savio was afraid of Peterson.

Pontarelli’s wife, Mary, was on the stand Tuesday. On the stand, she started to weep when she was shown a picture of Kathleen’s nude and lifeless body lying face down in the tub. She then recalled the moment when she ran inside the bathroom and found Savio’s body.

“I went into the bathroom and seen Kathleen. I ran out of the bathroom then, and threw myself on the ground, and started screaming,” she said.

Those screams brought Drew Peterson into the bathroom, where he took Savio’s pulse and discovered she was dead, according to Mary Pontarelli.

Peterson, a former Bolingbrook police sergeant, was charged May 2009 with the murder of Savio, whose body was found in a dry bathtub in March 2004.

Initially, Savio’s death was ruled an accidental drowning, but her body was exhumed after Stacy Peterson, Drew Peterson’s third wife, vanished in October 2007. After a new autopsy, officials concluded that Savio’s death was a homicide.

Prosecutors and Illinois State Police believe Stacy Peterson is dead, and Drew Peterson has been named a person of interest in her disappearance. But he has not been charged in that case.

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