Policewoman’s Suit Over Sex Inquiry Dismissed : Police: Kathleen Oborn fails to prove that police told a baby-sitter to search her home for evidence of an illicit relationship with a 16-year-old boy.

A federal judge dismissed a lawsuit Thursday brought by a Los Angeles Police Department female vice officer who claimed that department investigators violated her rights by telling a baby-sitter to search her home for evidence that she was having sexual relations with a 16-year-old boy.

U.S. District Judge Jesse W. Curtis Jr. found that Kathleen Oborn had not presented sufficient evidence that her baby-sitter, Allyson Di Conti, had taken property from her home at the request of investigators from the Internal Affairs Division.

Oborn, 34, who has been suspended without pay for improper conduct since late 1987, married and has since divorced the youth. She has denied she had a relationship with him before the marriage. She sought $10 million in damages in the lawsuit against the department and Di Conti.

The lawsuit centered on Di Conti’s March 27, 1987, visit to Oborn’s home, where she had formerly worked as a baby-sitter.

At the time, Di Conti, 23, had volunteered to help the Internal Affairs Division investigate allegations that Oborn was having an improper affair with Andre Rossky, a German exchange student who was living in Oborn’s home.

Di Conti wore a recording device and was invited in after knocking on Oborn’s door, according to court testimony. During the visit, Di Conti took letters, a cassette tape and other property and turned them over to investigators.

A day after the search, Oborn married Rossky in Las Vegas after he received the approval of his parents. Assistant City Atty. Robert Cramer said Rossky was 16 at the time.

Oborn filed suit the following year, charging that Di Conti was acting as a Police Department agent when she took the property without a warrant.

But during the six-day trial, Di Conti testified that the investigators told her not to take any property and only to engage Oborn in conversation. She testified that she took the property on her own initiative.

Di Conti, who testified that she went to police after seeing Oborn and Rossky engaged in a sex act in a garage, said she was motivated to help the investigators because she thought the relationship was damaging to Oborn’s four young children.

On Thursday, at the end of the presentation of Oborn’s case, Curtis issued a directed verdict, agreeing with defense contentions that there was insufficient evidence that Di Conti had been instructed to take property.

Oborn could not be reached for comment. Her attorney, Stephen Yagman, said the judge’s ruling would be appealed.

The filing of the lawsuit had delayed disciplinary action against Oborn, who was relieved of duty after the internal investigation resulted in eight counts of misconduct against her. Cmdr. William Booth, department spokesman, said that action will now proceed. Oborn could face firing after a Board of Rights hearing, he said.