Tactical officers from several police agencies swarmed to the tourist town of Lincoln City after a property manager at the WestShore OceanFront Suites recognized Michael Boysen's face and name after seeing him on television and called police early Tuesday morning.
Boysen, 26, checked in under his own name Monday night, motel owner Kent Landers told The Oregonian.
After a tense daylong standoff punctuated with water cannon blasts, bullhorn shouts and tear gas, officers stormed Boysen's motel room Tuesday evening.
They found him lying on the floor on his back with apparently serious self-inflicted cuts, Lincoln City police Chief Keith Kilian said.
He was flown to Legacy Emanuel Medical Center in Portland, where hospital spokeswoman Judy Pahl described his condition as critical late Tuesday night.
No officers were hurt in the standoff, which Kilian termed "very successful." Law enforcement officials in Washington state had described Boysen as extremely dangerous.
The bodies of Boysen's grandparents were found Saturday in their suburban Seattle home, a day after Boysen was released from prison and was greeted with a welcome home party. After those deaths were discovered, officials say they learned that Boysen had made threats against his relatives and law enforcement officials while behind bars.
Police spent much of Tuesday trying to persuade Boysen to surrender. After breaching the motel room door, they stormed in and captured him.
"We're certainly glad it's over and nobody else got hurt. We're glad they were able to take him into custody alive," King County Sheriff John Urquhart said in Seattle shortly after the capture.
Police used a robot equipped with a video camera and a microphone to communicate with Boysen. The robot was sent onto a balcony outside the motel room. Police finally breached the door, which Boysen reportedly had barricaded with a refrigerator.
When Boysen didn't come out on his own, police went in after him.
"We didn't know where to look," Urquhart said of the initial search. "We did publicity with hopes some citizen would see it and call 911 and that's exactly what happened. That's great."
King County sent two detectives to Oregon in hopes of talking with Boysen, Urquhart said. Depending on his medical condition, he'll have to go through extradition, then King County hopes to "get him back here for trial," the sheriff said Tuesday evening.
Boysen made threats against members of his family and law enforcement while locked up, Washington state Corrections Department spokesman Chad Lewis said Tuesday. But police didn't learn of the threats until after the bodies of the grandparents were found and authorities had started looking for Boysen.
"Sources went to our staff at the Monroe Correctional Center and told us he had been threatening to do all this," Lewis said.
The information was passed on to King County deputies, and that's why Sheriff Urquhart called Boysen extremely dangerous at a Monday news conference. Investigators also determined that Boysen had been searching the Internet for gun shows.
Boysen just finished serving nine months in prison on a burglary conviction, Lewis said. He had no violent infractions in prison - "nothing extraordinary," Lewis said.
He served a previous sentence between 2006 and February 2011 for four robbery convictions. Those convictions were related to an addiction to narcotic painkillers, Lewis said.
Boysen's grandparents picked him up from prison Friday and drove him to meet his probation officer and to get an identification card from the Department of Licensing. They hosted a welcome home party for him Friday night.
Boysen's mother discovered the bodies Saturday evening. She had been called by a family member who became concerned that the couple hadn't answered their door.
Authorities haven't said how they died.
The motive for the killings remains unknown, King County sheriff's Sgt. Cindi West said.
"Between the family and detectives we have no idea," she said. "It's just bizarre. The family loved and supported him the whole time he was in prison."
On Tuesday, the King County medical examiner's office identified the couple as Robert R. Taylor, 82, and Norma J. Taylor, 80. They died Saturday. The cause and manner of their deaths remains under investigation, the medical examiner said.
Urquhart said it was not known why Boysen fled to Oregon.
"We didn't know he had gone to Oregon, had no particular reason to look there."