A bright pink placard reading "Where's our sister Stacy?" was among half a dozen signs left during a vigil on the front porch of a former police officer suspected in the disappearance of his wife.

Marchers, some clutching candles, stood in front of Drew Peterson's home Saturday, many saying they would not rest until they know the whereabouts of Stacy, his fourth wife.

Stacy Peterson, a 23-year-old mother of two, has been missing since Oct. 28. Police have named her husband as a suspect in her disappearance, and authorities have called her case a possible homicide.

"I miss Stacy, and I'm not giving up," said her younger sister Cassandra Cales, choking back tears as she spoke on Drew Peterson's front lawn.

Taking part in the vigil were also relatives of Drew Peterson's third wife, Kathleen Savio, who was found dead in a bathtub in her home — located just a few minutes' walk from the house Drew Peterson shared with Stacy.

The vigil started at Savio's former home and ended at Drew Peterson's house. He drove away on his motorcycle before the vigil arrived but briefly looked over each of the signs on his porch when he returned later.

He told reporters outside his home after the vigil that the ordeal launched by his wife's disappearance has been hardest on his oldest children, who have to face questions at school.

"They're at that age where people like to tease and talk to them," Peterson said.

Stacy and Drew Peterson have two children, ages 4 and 2. He has two teenage sons from his marriage to Savio.

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Also Saturday, a renowned pathologist said he has examined Savio's exhumed remains and determined she was killed.

Former New York City chief medical examiner Dr. Michael Baden said he analyzed Savio's remains Friday at the request of her relatives, who disagree with an earlier ruling that her death was an accident. He concluded she died after a struggle, and her body was placed in the bathtub where she was found.

"I'm convinced she was the victim of a murder. 'Who done it' is up to the police to resolve," Baden said in a telephone interview.

Results of a separate, official autopsy will not be available for several days, authorities said.

A coroner's jury initially ruled that Savio's 2004 death was an accidental drowning. But authorities are now re-examining the circumstances around her death.

Peterson, 53, who resigned Monday as a Bolingbrook police sergeant, has not been named a suspect in Savio's death. He has an unlisted number.

He has denied any involvement in either case and said he believes his wife left him for another man and is alive.

Savio's body was exhumed Tuesday at the request of Will County State's Attorney James Glasgow, who has said after examining evidence he believes her death was a homicide staged to look like an accident.

Drew Peterson's other former wives have cast contrasting portraits of him, saying he could be charming and supportive, then controlling and abusive.

Peterson's first wife says he never threatened or abused her during their six-year marriage.

But Carol Brown tells the Chicago Tribune that he could be controlling. And while she was pregnant, she found out he'd been cheating on her.

Brown was married to Peterson from 1974 to 1980 after they met in high school.

Peterson's fourth wife, Stacy, has been missing since October 28th. Her disappearance has reopened the investigation into the death of his third wife, Kathleen Savio, who was found dead in a bathtub in 2004.

His second wife, Vicki Connolly, has said he could be both charming and controlling.

Brown wouldn't comment about whether she believes Peterson was involved in what may have happened to his other wives.