A 25-year-old man is accused of pushing a 78-year-old woman to the ground as he walked behind her on Northeast Broadway in an unprovoked attack that dislocated her shoulder and fractured bones in her face.

The woman fell face-first, striking a parked Prius about 5 p.m. Wednesday, police and a witness said.

Mike Nuss, an owner of RareBird Real Estate on Broadway, said he was in the office, walking to a conference room and heard a man outside scream, "I hate you.''

He looked out the glass windows of the office and saw a man suddenly knock the woman down. She had her back to the man, Nuss said.

Justin Dean Ames

Nuss ran to get his cellphone, called 911 and bolted outside. The woman was bleeding and had a gash beside her eye, he said.

She had parked elsewhere and then walked up to her friend's Prius. She was waiting for her friend to get out of the car when, Nuss said, "I saw him push her extremely hard."

The attacker kept walking, Nuss said.

"She did nothing to provoke this person,'' Nuss said. "She had her back to him. There was plenty of space for him to walk. She was just the wrong person in the wrong place at the wrong time.''

As the woman's friend helped her up, Nuss gave the dispatcher a description of the suspect and followed him for about one or two blocks. He saw the man, wearing a silver-colored raincoat, walk east on Broadway, then north on Northeast Ninth Avenue.

"It's terrible to know anything like that can happen out of nowhere as a citizen in our city,'' Nuss said. "It's a huge safety concern.''

Police looked at video surveillance footage from the real estate business and on Thursday arrested Justin Dean Ames, 25, as he was walking near North Larrabee Avenue and Broadway.

He was arraigned Friday in Multnomah County Circuit Court on a second-degree assault allegation. Ames, described as transient in court papers, told court officials that he's been diagnosed in the past with post-traumatic stress disorder and schizophrenia.

Police also learned that officers stopped and briefly held Ames at the Portland Expo Center on Wednesday night, accused of spitting at a security guard after he was told to leave the premises. Ames told officers he sleeps under the Fremont Bridge.

Ames has prior convictions for possession of methamphetamine, carrying a concealed knife, harassment and trespassing, court records show.

Police asked that anyone with more information about Ames contact Detective Travis Fields at 503-823-4104 or at Travis.Fields@portlandoregon.gov

-- Maxine Bernstein

mbernstein@oregonian.com

503-221-8212

@maxoregonian