SEATTLE — An intensive multistate manhunt reached a dramatic close Tuesday night as police in Oregon's Lincoln City stormed a beachfront motel room and arrested a man suspected of killing his grandparents.

SEATTLE — An intensive multistate manhunt reached a dramatic close Tuesday night as police in Oregon's Lincoln City stormed a beachfront motel room and arrested a man suspected of killing his grandparents.

Michael Boysen was taken into custody around 7 p.m. at the Westshore Oceanfront Suites following a 10-hour standoff.

Lincoln City police are reporting that he suffered self-inflicted wounds, but they do not appear to be gunshot wounds.

Sgt. Cindi West of the King County (Wash.) Sheriff's Office said Boysen was nonresponsive but alive when he was taken into custody.

Officers found Boysen lying on the floor on his back with apparently serious self-inflicted cuts, Lincoln City police Chief Keith Kilian said.

The 26-year-old man was flown to Legacy Emanuel Medical Center in Portland.

Hospital spokeswoman Judy Pahl described his condition as critical shortly after he arrived late Tuesday night.

Boysen, 26, is suspected of killing Robert Taylor, 82, and Norma Taylor, 80, at their home near Renton, Wash., last weekend just hours after he was released from a Washington state prison. Killian said officers had been using a public-address system to talk with Boysen sporadically throughout the day after a window in the motel was broken using a water cannon device.

"He had stopped talking to us and that got his attention," Killian said.

Police received a call about Boysen being at the motel around 7:30 a.m., after the property managers recognized his face and name on a morning news show, according to Killian.

Kent Landers, who owns the motel, said Boysen had checked in the previous night, using his real name and driver's license.

Police crept up to the Westshore early Tuesday, not wanting to alert Boysen, and silently evacuated the rest of the motel, he said.

Landers said this is usually a quiet time of year and only a few people were checked in when police arrived at his 20-unit motel. Lincoln City has a population of about 8,000.

Lincoln City police then settled in until Oregon State Police arrived with armored vehicles, a robot and a public-address system around 11 a.m. He said there was no telephone in the motel room.

"We said something like 'This is the police. You need to come out,' and he said, 'I don't want to. Go away,' " said Killian, who added, "We're not going away."

Killian said during the standoff that police had not seen any evidence that Boysen was armed. However, "King County said to consider him armed and dangerous and that's what we're doing," he said.

Negotiations with Boysen occurred on and off all afternoon, he said, and police were not in a rush as long as Boysen remained willing to talk.

Boysen had been sought since Saturday, when his grandparents were discovered slain in their Renton-area home. Investigators found that Boysen had been searching the Internet in an apparent effort to acquire firearms Investigators also learned Boysen had allegedly spoken of killing relatives and authority figures.

King County Sheriff John Urquhart said in a news conference Monday that Boysen should be considered armed and extremely dangerous. According to Urquhart, Boysen's grandparents picked him up from the Monroe Corrections Complex on Friday after he had served nine months of a 16-month sentence for a 2012 attempted residential-burglary conviction.

The couple then took Boysen to check in with his probation officer and to get an identification card. They brought him home and hosted a welcome-back party attended by numerous other relatives, who all told police Boysen had seemed "normal" and happy to be out of prison, Urquhart said.

He said Boysen is suspected of killing his grandparents sometime between 9 p.m. Friday and noon Saturday.

Boysen's mother discovered her parents' bodies around 5 p.m. Saturday when she used her key to enter the home, according to the Sheriff's Office. The cause of death has not been released by the King County Medical Examiner's Office.

Boysen had previously served five years in prison on four counts of robbery and possession of stolen property after he pleaded guilty to robbing several pharmacies and a grocery store.

He told police after his arrest that he was addicted to the narcotic OxyContin.