An undated photo provided by her family shows Stacy Peterson, 23, right, of Bolingbrook, Ill., with her younger sister, Cassandra Cales. Peterson, the wife of Drew Peterson, a sergeant with the Bolingbrook Police Department, was reported missing Oct. 29. Some residents of Bolingbrook are questioning why Peterson was never charged after police were called to his home 18 times in two years for domestic disturbances.

Bolingbrook, Ill. ? Eighteen times in two years, Bolingbrook police were called to fellow officer Drew Peterson’s home because of trouble between husband and wife. But Peterson’s wife could never get authorities to arrest him. In fact, she was the only one ever charged.

Now residents of this Chicago suburb are wondering whether police were protecting one of their own – and whether they bear some responsibility for what happened next.

Peterson’s wife at the time of the domestic disturbance calls, Kathleen Savio, was found dead in 2004 under mysterious circumstances. And now his current wife, Stacy, is missing and feared slain.

The way police dealt with Peterson “makes it kind of hard to trust cops,” said Pablo Delira, a 59-year-old construction worker. He said he has no doubt he would have been led away in handcuffs if police had been called to his house 18 times.

Kim Camplin, who works in the clothing business, said the two women might be alive today if Bolingbrook police had taken the domestic disturbance calls more seriously.

“It doesn’t matter if it’s a fireman, a policeman or a clergyman – all it should take is one call, and it should be taken seriously,” she said. “What faith can we have in the system?”

Peterson, 53, was a police sergeant and 29-year veteran of the force, resigning earlier this month after he came under suspicion in his current wife’s disappearance in October.

In a roughly two-year period beginning in 2002, police responded to 18 domestic disturbance calls at Peterson’s house. Savio accused Peterson of beating her and threatening to kill her, but no charges were ever brought against him.

Instead, Peterson twice persuaded prosecutors to charge Savio with domestic battery. She was acquitted both times.

Police Lt. Ken Teppel said that in all 18 instances, police conducted a thorough investigation. He said a department inquiry found no indication officers did anything wrong or violated procedure.

But Teppel acknowledged the case has damaged the department’s reputation.

“There is a distrust … that this is going to be covered up,” he said. “It’s so hard to get over that.”

Savio was found dead in her bathtub in 2004, and a coroner’s jury ruled it an accidental drowning. But since Stacy Peterson’s disappearance, investigators have re-examined Savio’s death and exhumed her body, and said they now believe it was a homicide made to look like an accident.

Peterson has not been named a suspect in Savio’s death. But authorities said he is suspected in Stacy Peterson’s disappearance. Peterson has denied wrongdoing in either case and said he believes his current wife left him for another man and is still alive.

The Bolingbrook department has handed the investigation over to the Illinois State Police – standard practice in criminal cases involving a member of the force.

Not everyone in the community of about 70,000 blames the department.

“I haven’t lost one iota of trust in the police department,” said Stephen DeFreeuw, a 16-year resident. “One rogue cop.”

Teppel said street cops in the 122-member department are being reminded about the proper way to handle domestic calls and are being told they are expected to adhere to the rules, no matter who answers when they knock on the door.

Teppel said Police Chief Ray McGrury has made it clear: “There are no favorites.”

Savio and Stacy Peterson were Peterson’s third and fourth wives. He and wives Nos. 1 and 2 divorced.

Vicki Connolly, Peterson’s second wife, has said that during their marriage, an increasingly controlling Peterson hit her and told her he could kill her and make it look like an accident.

Connolly said police sometimes came to the house when the couple were having problems, but she said the officers were friends of theirs and no reports ever were filed.