A federal magistrate ordered a science teacher at University City High School on Oct. 31 to be detained without bail on a felony charge of attempted enticement of a minor.

It is alleged that Sean Stevenson, 58, thought he was talking about a 16-year-old girl in a call with a prostitute, but he was actually talking in a recorded phone call to an undercover officer with the San Diego Human Trafficking Task Force.

His attorney told U.S. District Magistrate Judge Steve Chu it was not necessary to detain him and suggested Stevenson be allowed to be free on bond.

Assistant U.S. Attorney Derek T. Ko urged he remain in the Metropolitan Correctional Center where he has been since his arrest on Oct. 24. The magistrate agreed to detain him.

Stevenson has pleaded not guilty to the lone charge. He is on a leave of absence from the San Diego Unified School District. He also was a cross country coach at University High School.

The case has nothing to do with his job and no students were involved.

The case is in federal court because it is alleged he used a computer and telephone in violation of interstate commerce to engage in unlawful sexual activity with a minor. He didn’t actually have sex with any minor; rather he just allegedly talked about having it with a minor.

The investigation started on April 9 when a minor who was identified as a 16-year-old sex trafficking victim had her cellphone stolen and her pimp and another woman were arrested. On the woman’s phone was a message allegedly from Stevenson about an underage prostitute.

An undercover officer called Stevenson on Oct. 2 and pretended to be the same woman he previously talked to. “You still looking for what we talked about last time?” asked the officer. “Younger, yes,” replied Stevenson, according to a transcript in records. “I’ll pay well.”

The undercover officer asked him if he was still interested in her 16-year-old cousin. “I’m interested in her for sure!” replied Stevenson, according to a transcript.

Stevenson offered to pay $140 for oral sex without a condom with the 16-year-old cousin in his car, according to records. Stevenson showed up on Oct. 24 in the 5300 block of El Cajon Blvd. where the undercover officer directed him.

A search of his car uncovered $140 in cash along with a black Samsung smartphone, which rang after an officer called it. He was then arrested.

A preliminary hearing was scheduled for Nov. 21 in U.S. District Court.