A man suspected in the disappearance of a Vermont collegian who turned up dead last week denied having anything to do with it when police interviewed him, according to court papers filed Monday.

Police, meanwhile, said for the first time that 21-year-old Michelle Gardner-Quinn was a homicide victim. They would release no other findings from the autopsy, conducted Saturday.

"The cause of death will be listed as soon as test results from the medical examiner and additional information from the investigation becomes available," police Lt. Kathleen Stubbing said late Monday.

In the affidavit, Brian L. Rooney, 36, told police he walked up Main Street in Burlington with the woman at about 2 a.m. on Oct. 7 but parted ways from her.

"He advised he separated from Gardner-Quinn at that point and he never saw her again. Rooney denied having any knowledge or involvement in Gardner-Quinn's disappearance," according to the affidavit by Detective James Claremont of the Vermont State Police, released just before a court appearance in which Rooney pleaded not guilty to sex charges unrelated to the college student's disappearance.

Her body was found Friday at the top of a gorge in Richmond, about 15 miles east of the University of Vermont, where she was a senior.

Rooney, who was arrested Friday and charged with sexual assault and lewd or lascivious conduct with a child, has been named by Burlington police as a suspect in Gardner-Quinn's death but he has not been charged with it.

Monday's court appearance focused primarily on the sex charges, which were filed based on information police said came to light as they investigated the disappearance.

In the affidavit, filed in Vermont District Court in St. Johnsbury, 80 miles east of Burlington, witnesses accuse Rooney of using chemical-soaked rags or other substances to render victims unconscious and unable to resist his sexual advances.

Rooney is accused in the affidavit of molesting a girl in 1996 and 1998, when she was 12 and 14, respectively, and it says he made advances toward the girl's sister.

Rooney is charged with lewd and lascivious conduct with a child, accused of fondling her in 1996 while in St. Johnsbury. He has also been charged with sexual assault, accused of drugging the girl in 1998 and having sex with her at his home in East Concord.

Lawyer David Sleigh entered a not guilty plea on Rooney's behalf in district court. Rooney spoke only to his lawyers.

Judge Kathleen Manley set bail at $150,000.

Sleigh tried unsuccessfully to have the charges thrown out, saying there was insufficient probable cause to support them and questioning why the decade-old charges were being filed now.

He called the charges a "peremptory strike" by police investigating the Gardner-Quinn death.

Rooney's ex-wife, identified only by initials in the affidavit, obtained a restraining order against him in April 2000, according to the affidavit. She accused him of drugging her "many times so he could rape her."

She also accused Rooney of threatening at least once to kill her, according to the affidavit.