A 24-year-old man is accused of assaulting a MAX Blue Line operator after he was told to get off the train, according to Portland Police spokesman Sgt. Chris Burley.

Steven Caldwell

Steven Caldwell was yelling about First Amendment rights, according to witnesses and the operator, when the train driver told him over the loudspeaker to quiet down. Burley said that the operator notified Caldwell that he would be kicked off the train if he kept yelling, but Caldwell continued.

At the East Burnside and 102nd Avenue stop, the operator walked up to Caldwell and asked him to leave. Then, Caldwell attacked the operator with his fist and his foot, Burley said.

Passengers pulled the operator away from Caldwell, who ran away.

The first call for police came from TriMet dispatch around 2:15 p.m., saying the suspect was on foot.

East Precinct officers soon found Caldwell and arrested him near Southeast 103rd Avenue and Southeast Ankeny Street. He is in Multnomah County Jail.

The operator was examined by emergency medical crews, but was not taken to the hospital.

Police are looking for anyone who saw what happened on the train or has cell phone video of the incident. You can call the non-emergency police number at 503-823-3333.

"We also want persons to know we have an increased presence of transit police, TriMet security and fare inspectors on the system," Burley said. "If anybody sees anything that concerns them or a person that causes them concern, do not hesitate to contact police through 911 or the non-emergency line."

The security presence was increased after three people were stabbed on a MAX train last week.

Assaults on TriMet drivers and train operators are up in recent years, prompting the agency to try to increase penalties for the assailants and better protect transit employees.

-- Molly Harbarger

mharbarger@oregonian.com

503-294-5923

@MollyHarbarger