Portland Police Chief Larry O'Dea has decided to retire, ending a nearly 30-year career amid criminal and internal investigations for an off-duty shooting of a friend during an eastern Oregon camping trip, his attorney confirmed Sunday.

Mayor Charlie Hales, who serves as police commissioner, is expected to make the announcement Monday morning.

Hales will appoint a captain - someone other than the four assistant chiefs under an administrative investigation themselves -- to serve as interim chief until a successor is determined, likely after Mayor-elect Ted Wheeler takes office in January, multiple sources told The Oregonian/OregonLive.

O'Dea's lawyer, Derek Ashton, said O'Dea "did not knowingly discharge a firearm in the direction of his lifelong friend.'' O'Dea also contends he was not intoxicated or impaired by alcohol at the time of the shooting, and is confident the criminal investigation by the state police and Oregon Department of Justice will not result in charges and clear up "gross misstatements of facts contained in early reports,'' his lawyer said.

"His thoughts and prayers have been with his friend from the moment the accident occurred. Larry has always placed the security, health and well-being of others above himself while focusing on the greater good for the citizens he served and the Portland Police Bureau,'' Ashton said Sunday. "With those priorities in mind, he has decided to retire.''

The mayor's spokeswoman Sara Hottman alerted media on Saturday that Hales will be holding a press conference at City Hall at 10 a.m. Monday. She declined to discuss the subject. Hales, who was out of town attending a U.S. Conference of Mayors meeting in Indianapolis, could not be reached.

O'Dea, 54, and the mayor kept the April 21 shooting out of the public eye for nearly a month, until reporters questioned the bureau about it in late May. On May 20, the chief acknowledged that he had a "negligent discharge" of his .22-caliber rifle and shot his friend. The friend, Robert Dempsey, wounded in the lower left back, was airlifted to a trauma hospital in Boise, Idaho, where he was treated and released.

But when a Harney County deputy responded to a 911 call after the shooting, O'Dea suggested the shooting had been self-inflicted, according to the sheriff and sheriff's reports.

O'Dea told the Harney County deputy that his friend may have accidentally shot himself while putting his pistol in his shoulder holster while they were shooting ground squirrels, sheriff's reports show.

The deputy reported smelling alcohol on O'Dea's breath, his report said. O'Dea had told the deputy he didn't have his rifle in his hand at the time, but was reaching for a drink out of a cooler and heard his friend scream. But O'Dea sometime later called Dempsey to apologize for shooting him. After his release from the hospital, Dempsey was interviewed by the deputy and said that O'Dea had been having trouble with his rifle all day, that it was jamming and misfiring. Dempsey also told the deputy that O'Dea said he went back to his chair and when he picked up his rifle, it accidentally went off.

O'Dea never told Harney County sheriff's office that he was responsible for the shooting, Sheriff Dave Ward has said.

Dempsey informed Harney County Sheriff's Office that O'Dea was Portland's police chief. Harney County Sheriff's Office called in Oregon State Police to take over the criminal investigation.

Statement by Larry O'Dea's lawyer, Derek Ashton

"Larry O'Dea did not have alcohol on his breath nor was he impaired or intoxicated. He did not purposely point his gun at any person and did not knowingly discharge a firearm in the direction of his lifelong friend. His thoughts and prayers have been with his friend from the moment the accident occurred. Larry has always placed the security, health and well-being of others above himself while focusing on the greater good for the citizens he served and the Portland Police Bureau. With those priorities in mind, he has decided to retire. Looking forward, he is confident that the Oregon State Police and State Department of Justice will very soon conclude a professional and competent investigation of this camping accident that will clear up gross misstatements of facts contained in early reports."

State police, assisted by the state Department of Justice, are continuing the criminal inquiry, which is expected to be completed soon.

The city's Independent Police Review Division in late May also initiated a separate administrative review into why O'Dea, the bureau's four assistant police chiefs and the internal affairs captain didn't call for an internal investigation themselves. O'Dea told all five colleagues about the shooting.

He also told Hales four days after the shooting, but the mayor kept it under wraps and didn't put O'Dea on paid administrative leave until May 24, a day after details emerged that the chief initially had described the shooting as a self-inflicted accident to a Harney County deputy.

O'Dea has never publicly commented on the circumstances.

The retirement would add to the controversy surrounding O'Dea. If he were treated like other officers under criminal investigation, he should resign, not retire and not be allowed to get a retirement badge, some rank-and-file officers say.

If O'Dea faces criminal charges in the April 21 shooting or an internal inquiry finds he lied about its circumstances, he could still lose his police certification even after retiring.

Police Capt. Mike Marshman is the likely candidate to temporarily replace O'Dea, sources said.

Marshman is the police liaison with the U.S. Department of Justice regarding the settlement agreement reached with the city after a 2012 federal investigation found Portland officers used excessive force against people with mental illness. Marshman's title in the bureau currently is DOJ compliance coordinator. He previously served as a public spokesman and as executive assistant to former Police Chief Mike Reese.

O'Dea served as chief for a year and a half after rising steadily through the ranks. Hales appointed him to lead the bureau starting in January 2015 after Reese retired. O'Dea joined the Portland force on Sept. 4, 1986.

O'Dea made $192,504 a year in the top job. His annual pension would be about 82 percent of that, or about $160,000, depending on the percentage he chooses for survivor benefits.

It's not clear if the mayor or the city has made any other severance agreement with O'Dea.

Under a contract with the city, he would receive severance of one-year's pay if he was fired without cause. His salary and benefits would end if he was fired with cause, but he'd still collect his pension. Typically, such firings involve serious misconduct, a violation of city rules regarding ethics or a conviction for any crime that could bring discredit to the city.

When he was sworn in as chief, O'Dea cited four goals: building trusting relationships with people in all parts of the city, increasing diversity within the bureau and its leadership, increasing police collaboration and communication, both within the bureau and with the community, and making sure the bureau was fiscally responsible.

His departure comes as the beleaguered bureau is struggling with a serious staffing shortage and considering eliminating several specialty divisions, including the neighborhood response teams and street crimes units, to send officers back to patrol to fill about 65 vacancies.

The state of community police oversight groups also are at a low point - two leaders of the new advisory board created to oversee police reforms under the federal settlement have resigned and meetings of the city's Police and Community Relations Committee that had been addressing racial profiling concerns have been canceled for at least two months.

Assistant Chief Donna Henderson, who led the investigations branch under O'Dea, is currently acting as chief. The mayor named her acting chief on the day he placed O'Dea on administrative leave in late May.

-- Maxine Bernstein

mbernstein@oregonian.com

503-221-8212

@maxoregonian