(CNN) -- Despite defense criticisms of what it called a "shameful" leading question about whether Drew Peterson tried to intimidate a neighbor, a judge ruled Thursday that the former Chicago-area police officer's murder trial can proceed.
Five witnesses took the stand in Joliet on Thursday, but not before lawyers from both sides argued about whether a mistrial should be ordered, thus bringing the entire case back to square one.
This debate followed testimony Wednesday by Thomas Pontarelli, a Bolingbrook, Illinois, neighbor of Peterson's ex-wife Kathleen Savio and one of those who found her dead in a dry, clean bathtub on March 1, 2004.
Pontarelli testified Savio had asked him to put a lock on her bedroom door and also that Peterson had once challenged him about the front door locks at Savio's house being changed, which Pontarelli insisted he didn't do.
The night of March 1, he said Peterson -- a police officer in Bolingbrook who was barred from seeing Savio by a protective order -- called the Pontarelli house to say a locksmith was coming to get in his ex-wife's house. After the door was unlocked, Pontarelli, some of his family members and Peterson came across Savio's body, with no rug or towel nearby, in an upstairs bathroom.
Later, prosecutor Kathy Patton brought up the time Peterson questioned Pontarelli about whether he'd changed the locks of Savio's front door, asking him, "Did there come a time when you felt intimidated by him?"
"Yes," Pontarelli responded. "We had a conversation. He accused me of changing the locks on the front door. I (said) I didn't, but I got his message ... I found a .38 bullet out on the driveway."
After this statement, defense lawyer Steven Greenberg objected and subsequently Judge Edward Burmila asked the jurors and the witness to leave the courtroom.
On Thursday, Greenberg argued for a mistrial, saying, "(Prosecutors) are going to try and continue ... to put in evidence that people were fearful of Mr. Peterson ... So far, we have a jury that thinks everybody's afraid of Mr. Peterson. How is that fair to Mr. Peterson?"
Calling the state's question leading and unfair, the defense lawyer added that prosecutors were acting as if "the rules of evidence don't apply to them," which he called "shameful."
Prosecutor Chris Koch, in response, said it was "absurd" to suggest the state was "trying to mislead this jury."
The judge ruled the question and response was inadmissible, later instructing jurors to ignore it and any reference to a bullet. But he also said the trial should continue and that the jury could consider the rest of Pontarelli's testimony.
With this issue settled, the trial resumed with the testimony of Louis Oleskiewicz, the paramedic who saw Salvo "down in the bathtub" with no pulse. He spoke about her hair being matted down and skin feeling cold and "waxy."
Oleskiewicz said he didn't see any towels to suggest Savio might have been taking a bath, questioning whether a blue towel shown in a picture from the scene was actually there that night.
A locksmith, Robert Akin, took the stand next to discuss being called -- with a call straight to his cell phone, even though he was not on call for his shop that night -- and unlocking the front door of Savio's house, with Peterson standing next to him flashlight in hand.
Three Bolingbrook firefighters later testified about their experience at the Savio house that night, noting the presence of several people, including Peterson. Two of them said Peterson, who was in uniform, asked them to be respectful of the scene because it was his ex-wife.
Testimony will resume Friday and, after a three-day weekend, pick up on Tuesday. The entire trial is expected to last about four weeks.
Peterson, now 58, was married to Savio in 2001 when he had an affair with then-17-year-old Stacy Kales, who later became Peterson's fourth wife. He has been called a suspect in her 2007 disappearance, though he's never been charged and she has never been found.
Savio and Drew Peterson filed for divorce that October, and their relationship remained contentious for the next several years.
Bolingbrook police records indicate officers were called to Savio's home 18 times to intervene in domestic fights from 2002 to 2004. Drew Peterson had Savio arrested twice for domestic violence, though she was found not guilty in both cases.
A judge in March 2002 granted Savio a protection order from her ex-husband, prohibiting him from being near her, entering her home or taking out their children except for two brief weekly visits.
Savio had claimed that months after that order was issued, Peterson held a knife to her throat and threatened to kill her inside her home.
On February 27, 2004, Peterson picked up his two sons from Savio's home, spending the next two days with them. Prosecutors believe that he entered her home again early on February 29 and killed Savio.
At the time of her death, which authorities initially treated as an accident, a court was mulling how the couple's marital assets would be divided, and Savio was set to receive part of Peterson's pension and other support.
During opening statements Tuesday, one of Peterson's lawyers argued that their client spent his career protecting the public and that murder accusations are groundless.
"Kathy slipped, fell, hit her head in a household accident, and drowned. Case closed," said attorney Joel Brodsky.
InSession's Michael Christian in Joliet contributed to this report.