When Dennis DeRenzo's wife reported him missing from their Baldwin Borough home four years ago, police embarked on an intense two-month manhunt that yielded nothing but dead ends and disappointments.

Tips led them all over Baldwin, to mines in South Park, to Clairton and to the riverbanks. Baldwin police recruited the help of the Pennsylvania State Police, who searched in a 50-mile radius around Baldwin from a helicopter, and retired Pittsburgh police commander and homicide Detective Ron Freeman. Even information from a psychic, who faxed in a note that she had visions of Mr. DeRenzo's body tangled in weeds, led searchers to check the weeds in any area that they may be searching. Today, it remains the borough's only open missing person case, said Chief Michael Scott.

But on Saturday, just two days before the four-year anniversary of Mr. DeRenzo's disappearance, there was a break in the case. In Washington County, California Borough police were pulling another man's car from the Monongahela River after it accidentally slid in when they came upon a Chevy Silverado that Mr. DeRenzo's mother, Nancy, had loaned to him around the time of his disappearance. Inside, they found remains.

Anthropologists from Mercyhurst College are working to determine whether the remains are human and, if they are, an autopsy will be performed today, Chief Scott said. State police, who took over the investigation, and Washington County Coroner Timothy Warco released no information about the case yesterday.

Chief Scott called it "ironic" that a break in the case would come now. When he took over as chief in August, he reviewed all of the department's unsolved cases and discussed taking a fresh look at the DeRenzo disappearance.

"We talked about it and we decided ... that after the G-20 [summit] that we were going to make an appeal for any information regarding his disappearance," he said.

Police have long suspected that there was foul play involved in Mr. DeRenzo's death but got conflicting accounts of where he was the night he didn't come home. Acquaintances talked about a party that they believed Mr. DeRenzo was at somewhere in Baldwin and reported that when they called people at the party, they heard loud noises in the background and "felt something had happened" to Mr. DeRenzo. But others said he was never at the party, Chief Scott said.

Then came the psychic, who volunteered her services after she heard about Mr. DeRenzo's disappearance. She told police she believed he had gotten in a fight with someone because he was upset about witnessing the murder of a friend and had died in the fight. Police, desperate for a break in the case, checked the story with friends and could not substantiate it.

Today, four years to the date that Mr. DeRenzo was reported missing, many questions remain about his disappearance. But Chief Scott is hoping the silt- and mud-covered pickup that was pulled from the river Saturday will provide some answers.