Story updated at 5:30 p.m. Friday.

A sex offender with a long record and compulsion for public indecency was sentenced to life in prison without parole Friday for his latest offense -- getting caught masturbating on a MAX train.

Terry E. Iversen, 49, was sentenced after a three-hour hearing in Washington County Circuit Court in which Judge Oscar Garcia heard from the defendant's victims, current and retired detectives who investigated sex-related cases where he was either convicted or not charged, and a probation officer who advocated Iversen spend the rest of his life behind bars.

Iversen pleaded guilty to public indecency in January, a felony because of his past sex-related convictions. The true life sentence is permitted under a "three strikes"-like Oregon law aimed at predatory sex offenders.

"I think it was the right call," said Allison Brown, the county deputy district attorney who prosecuted the case and asked the judge for the life sentence. "He has continued to show that he won't benefit from treatment or rehabilitation, and at that point it's about protecting citizens and preventing him from crimes like this or worse."

She said Iversen had been sentenced to sex offender treatment at least five times but never completed it or stopped his behavior.

Terry Beach, Iversen's attorney, didn't immediately respond to a request for comment Friday. He wrote in a sentencing memo that he felt his client's punishment didn't fit the crime and suggested a prison sentence of eight years and four months.

The defense attorney argued Iversen's only conviction for a sex crime that involved physical contact was in March 1989 in Washington County for third-degree rape of a 15-year-old and second-degree sodomy of a 12-year-old girl.

Before Iversen was arrested in October, his most recent public masturbation conviction was in 2000, which was a felony because of his past sex crimes, Beach noted.

"(Iversen) took steps to satisfy a compulsion in a way that minimized the impact it would have on others," Beach said in a sentencing memo. "Such actions do not deserve a life sentence without parole."

A life sentence for multiple felony sex crimes is unusual in Washington County, Brown said, but it's unclear how typical it is statewide.

The Oregon Supreme Court last year overturned a life term as too harsh for a man convicted of public indecency, but it upheld life terms for at least two others in felony sex-related cases.

Court records show a string of past public indecency convictions for Iverson - in 1985, 1996 and 2000, including on public transportation in Washington and Multnomah counties. He also has been convicted of burglary, escape and drug possession.

He got out of prison last year after spending more than 12 years behind bars for assault and other crimes during a police chase that began when he was reported to be following young girls around a shopping center. He crashed into two cars and injured three people during the case in Cedar Mill.

Once out of prison, he was ordered to stay at the Washington County Community Correctional Center but got in trouble again, records show.

He masturbated while sitting behind a woman on a MAX train in Hillsboro in September, Brown said. The woman got off the train and called police, but they couldn't find the suspect.

In October, Iversen sat behind another woman while heading back to the community corrections center in Hillsboro and masturbated behind her. He placed his jacket next to him to block the view of anyone across the aisle, but the woman turned and saw him. Police later arrested him.

Surveillance video linked him to the earlier incident, Brown said, but he was never charged.

Beach said Iversen has been diagnosed with a mental health disorder that causes compulsive sexual behavior. He was responding positively to sex offender treatment after his latest stint in prison but couldn't avoid any of his triggers while on the MAX train in October so he "quietly masturbated," the lawyer said.

He has cooperated with police and taken responsibility for his actions, Beach said. He initially was scheduled to go to trial but opted to plead guilty instead that day to avoid having the victim testify in court, Beach said.

Beach cited the state Supreme Court's decision last year overturning the life sentence of Dennis J. Davidson, who was sentenced in Marion County for masturbating near women while behind a tree in a Salem park and again in front of police officers while standing at a fence in the area. He had three earlier convictions for public indecency.

The court concluded that because Davidson had no sex offense more serious than public indecency, a life sentence without parole would be unconstitutionally disproportionate under Oregon law.

"Unwillingly observing sexual behavior by another person is not a harm of the same magnitude as being specifically and personally subjected to unwanted physical sexual contact or sexual violence," the Supreme Court opinion said.

Davidson is scheduled to be resentenced in April. The prosecution plans to request a sentence of 16 years and eight months.

Brown cited two cases that the Supreme Court upheld last year:

-- The court concluded Douglas W. Sokell's life sentence was appropriate. He had been convicted in Washington County of first-degree sexual abuse for touching an 8-year-old girl's buttocks and hips in a public library. He had two prior sexual abuse convictions involving children.

-- The court noted that William M. Althouse's criminal history justified a life sentence. He had been sentenced for public indecency in Marion County -- his fourth conviction for a felony sex crime, which included two other cases that involved children. In the latest case, Althouse was spotted by a jogger sitting without pants near a popular running path and within 150 feet of a middle school.

The court noted that someone's inability to correct behavior after several opportunities could support a life sentence.

-- Everton Bailey Jr.

ebailey@oregonian.com

503-221-8343; @EvertonBailey