Police are asking for help finding a man suspected of stealing the wedding ring and backpack of one of Friday's MAX stabbing attack victims.

The ring and backpack belong to Rick Best, one of two men slain in the attack, police said. Best, 53, was a father, Army veteran, city of Portland employee and onetime candidate for Clackamas County commissioner.

He was headed home to Happy Valley when he and others came to the aid of two girls who were the target of Jeremy Joseph Christian's racist vitriol, according to police and witnesses. Christian is accused of pulling a knife and striking three men who came to the girls' defense, killing two of them.

Police have released surveillance images and video of the suspect. The video shows him leaving the train while holding two backpacks — one of which belongs to Best and contained personal items that are important to his family, police said. Police don't know who the other backpack belongs to.

When asked whether Best was wearing the ring, a Portland police spokesman said detectives don't want to release specific information until they make an arrest in the case.

In a news release Thursday, police described the suspect as a man with a blond mullet who was wearing a Jordan baseball cap, black T-shirt with an image of Marilyn Monroe and an American flag, and black shorts and shoes.

They ask anyone who can identify the suspect or knows the location of the stolen items to email Detective Mitch Hergert at mitchell.hergert@portlandoregon.gov.

Police urge the suspect to call 503-823-3333 or go to the police bureau's Central Precinct if he wants to turn himself in.

Christian, the stabbing suspect, appeared briefly in court Tuesday on nine charges -- two counts of aggravated murder, attempted aggravated murder, first-degree assault, two counts of intimidation and three counts of unlawful use of a weapon.

— Jim Ryan

jryan@oregonian.com

503-221-8005; @Jimryan015

Maxine Bernstein and Elliot Njus of The Oregonian/OregonLive staff contributed to this report