A man convicted five times of exposing himself in public was arraigned Wednesday on another charge of public indecency for allegedly masturbating on the steps of a Northwest Portland synagogue.

Authorities say they received a call that Alan Bruce Robinson, 48, had pulled down his pants at Congregation Beth Israel on Tuesday afternoon while children were attending an afterschool program at a charter school on the property near Northwest 19th Avenue between Flanders and Glisan streets.

Alan Bruce Robinson, 48, was arrested on Tuesday, Jan. 7, 2020 under allegations of public indecency. (Multnomah County Sheriff's Office)

A probable cause affidavit offers no indication that children saw Robinson. But the affidavit does say a man walking his dog spotted Robinson, told him to leave, then told someone at the charter school and that person called police.

Robinson had been convicted of public indecency in 1994, 2001, 2012, 2015 and 2018.

Robinson was sentenced to about two years in prison in 2015, after a woman reported she was walking with her baby through Farragut Park in North Portland when she saw Robinson masturbating. He received an identical sentence in 2018 for doing the same on the lawn in front of De La Salle High School in North Portland.

He is homeless and lists his address as the Portland Rescue Mission on the west side of the Burnside Bridge. He is required to register as a sex offender and last reported his address to authorities as under the St. Johns Bridge.

Robinson told jailers that he lives off Social Security disability and has mental health problems, but didn’t specify a diagnosis.

-- Aimee Green

agreen@oregonian.com

o_aimee

Visit subscription.oregonlive.com/newsletters to get Oregonian/OregonLive journalism delivered to your email inbox.