KING COUNTY SHERIFF'S PHOTO

Robert R. Porter.

A convicted child molester who is accused of leering at a young girl at the Shoreline Public Library is back behind bars as King County prosecutors seek to have him civilly committed.

Robert R. Porter, 40, was arrested Friday and ordered held without bail. Senior Deputy Prosecutor Hugh Barber said in a court filing that the state wants to have Porter held in jail and evaluated because of the recent "overt acts" involving the child at the library, the court filing said.

Under Washington state law, sex offenders can be confined indefinitely if it's determined they're a danger to the public.

Porter was convicted of first-degree child rape and first-degree child molestation in Clark County in 1995, Barber said in his filing. Porter's victims included three 10-year-old girls, according to a sex offender notification on the King County Sheriff's Office Web site.

While serving an 11-year prison sentence, Porter participated in sex offender treatment and was diagnosed as having a Mental Abnormality of Pedophilia, an illness that would make him likely to engage in acts of violence if not confined to a secure facility, prosecutors said. Between his prison release in 2006 and 2009, Porter was on probation.

The King County Sheriff's Office started investigating him again earlier this month after receiving a phone call from his roommate, prosecutors said. The roommate said that Porter told him about the Oct. 4 incident at the library. Library staff told investigators that they kicked Porter out of the building after the mother of a 3- or 4-year-old girl reported that the man had been leering at the child.

Investigators talked to Porter on Oct. 8 and he said he was watching little girls at the library that day and was "fixated" on one particular child because she was "perfect," charging papers said. Porter told detectives that he hoped to follow the girl into the restroom so she could perform a sex act on him, the papers said.