A Clackamas County sheriff's deputy swiftly subdued a man who wouldn't acknowledge his identity in court last year, then drove him to the ground as the man shouted in confusion, according to a video of the altercation.

The video, obtained Thursday by The Oregonian/OregonLive, shows Deputy Dan O'Keeffe walking across a courtroom at the Clackamas County Courthouse as Ronald Strasser's case was called. O'Keeffe is under criminal investigation in the confrontation.

Another deputy, who has since retired, alleges that O'Keeffe last year asked to be placed in a courtroom with Strasser so he could "beat the crap out of him."

O'Keeffe was assigned a few weeks later to a courtroom where Strasser was to appear on a trespassing case.

In an exchange with Circuit Judge Jeffrey Jones, Strasser refused to acknowledge his identity.

O'Keeffe spoke up. "Your honor, he is here," the deputy said.

"Are you Mr. Strasser?" Jones asked.

"No, I'm not Mr. Strasser, but I am here in regards to that matter," Strasser said.

"Oh, OK," the judge said before issuing an arrest warrant because of Strasser's refusal to acknowledge his identity. "Then it'll be a $25,000 warrant."

At that point, O'Keeffe crossed the courtroom and approached Strasser.

"Pardon me?" Strasser asked.

As the judge repeated the warrant information, O'Keeffe reached for Strasser's arm, then pushed his head and forced his body to the ground as Strasser called out, "What's the matter? What's the problem? I am here in regards to this matter!"

The courtroom disturbance first emerged when retired Deputy Joel Manley notified the county in March of his plans to sue for harassment and retaliation.

He said he was the target of two internal affairs inquiries and isolated by coworkers after he refused to participate in an off-color photo shoot at the courthouse last fall.

The Clackamas County District Attorney's Office dropped the case against Strasser once prosecutors learned of Manley's allegations. Prosecutors also asked an outside police agency to open a criminal investigation into O'Keeffe. That investigation is ongoing, the Multnomah County District Attorney's Office said this week.

Clackamas County Sheriff Craig Roberts did not immediately respond to an email seeking comment.

-- Noelle Crombie

503-276-7184

@noellecrombie