PORTLAND, Ore. » A boyfriend and girlfriend suspected in a string of grisly killings across the Pacific Northwest say they killed the man’s father because he molested two young relatives and his wife because she knew about it and didn’t stop him.

Police say David "Joey" Pedersen and his girlfriend, Holly Grigsby, who are both known to have white supremacist beliefs, then continued on a bloody crime spree that swept the region for days, eventually killing a man in Oregon they thought was Jewish, and another man in California who was black.

Joey Pedersen, 31, said in a jailhouse interview published in a California newspaper that he takes "full responsibility" for all four killings. But Grigsby, 24, has told police that one of the deaths came at her hands.

Pedersen told The Appeal Democrat in a story published Monday that his plan to kill his estranged father, David Jones "Red" Pedersen started with catching a ride to a bus station.

Red Pedersen, 56, got behind the wheel of his black Jeep Patriot. Grigsby sat up front in the passenger seat. And Joey Pedersen sat behind his father — so he could shoot him in the back of the head as he drove.

Grigsby reached over, took control of the vehicle and brought it to a stop.

From there, Grigsby told police, the couple returned to the older Pedersen’s home in Everett, Wash., where she says she killed Red Pedersen’s wife, Leslie Pedersen, with a pair of knives. Grigsby claims Leslie Pedersen, 69, was aware of the molestation they accused Red Pedersen of committing, yet did nothing to put an end to it.

Everett police Sgt. Robert Goetz said officers have not yet looked into the molestation allegations but planned to do so. He said evidence collected so far indicates much of Grigsby’s story could be plausible.

Attempts by The Associated Press to reach Joey Pederson and Grigsby at the Yuba County, Calif., jail were not successful Monday.

As Joey Pederson made the molestation claims against his father, he attempted to take focus away from Grigsby.

"I felt it was my responsibility to make sure it didn’t happen again," Joey Pedersen told the newspaper.

He said Grigsby was involved in the slayings only under duress and shouldn’t be held accountable for the deaths. Joey Pedersen said he takes "full responsibility" for all of the killings.

Pedersen and Grigsby have pleaded not guilty to charges of weapons possession and vehicle theft. They were expected in court Tuesday afternoon for an extradition hearing. They have not been charged in any of the killings.

Their appointed attorney, Donald Wahlberg, said he did not know anything about the case beyond what had been reported.

Leslie Pedersen’s body was discovered on Sept. 28. Her hands were bound with duct tape, a bloody pillow was by her head.

But, authorities say, Joey Pedersen and Grigsby were by then already on the run — and nowhere near finished.

They drove Red Pedersen’s Jeep south toward Oregon, his body still inside the vehicle. Three days later, they encountered 19-year-old Cody Myers, a devout Christian, on his way to a jazz concert on the Oregon coast.

Myers was shot in the head and chest, and his body was discovered hidden in the woods.

"Cody was devoted to his family. He would’ve done anything for anybody to help anybody," Susan Myers, told reporters at a news conference the day his body was identified last week. "He had passion for life, for God, for his beliefs. He didn’t deserve this."

According to court documents obtained by KGW-TV, Grigsby said they killed Cody because based on his last name they thought he was Jewish.

Investigators say Joey Pedersen and Grigsby ditched Red Pedersen’s truck. Authorities found it days later in forest terrain so rugged it took them hours to find Red Pedersen’s body inside.

The couple continued south in Myers’ Plymouth Breeze and, police say, within days encountered 53-year-old Reginald Alan Clark, who was found dead with a bullet wound to the head in Eureka, Calif. Other details surrounding the death are unclear and police have not suggested a motive, but Clark is black.

Joey Pedersen and Grigsby were apprehended Wednesday when a California Highway Patrol officer spotted them in Myers’ car.

Joey Pedersen has an extensive criminal history, having spent the ages of 16 to 31 behind bars, except for a one-year stretch. His convictions include assaulting a police officer and threatening a federal judge, and other disciplinary infractions included assault, extortion, disobedience, harassment and destruction of property.

He was released from prison in May.

Grigsby also spent time in prison beginning in 2006 for a variety of charges, including identity theft and unauthorized use of a vehicle. After completing probation, she served two years for identity theft. Even in prison, she got into trouble for assault and possession of contraband.

Both share an interest in white supremacist ideology. Pedersen prominently displays a white supremacy tattoo on his neck. Grigsby’s white supremacist leanings were made clear to fellow inmates at Oregon’s women’s prison.