Pedersen said he couldn't sit idle while "Western identity is being destroyed by other cultures," and he regretted that police intervened before he did more damage.
"I offer no excuses because none are needed," he said.
Pedersen, 34, and his girlfriend, Holly Grigsby, went on the rampage during nine days in 2011 as part of a campaign to purify and preserve the white race. Grigsby was sentenced to life in prison last month.
Pedersen was sentenced Monday for the carjacking murders of an Oregon teenager the couple mistakenly thought was Jewish and of a black man in Northern California.
Pedersen told those in the Portland federal courtroom that the sentencing was "rather anti-climactic," because he had already been sentenced to life in prison in Washington state for the deaths of his father and stepmother.
Though there was never any doubt about Pedersen's guilt, the federal case hit a snag when it was revealed that investigators failed to share information with the defense, as required, and that prosecutors obtained recordings of phone calls made by Pedersen that included confidential defense strategy.
With that leverage, Pedersen accepted a plea agreement that netted lighter sentences for a couple who helped Pedersen and Grigsby during the spree.
Pedersen also personally benefited from the deal by getting a grilled salmon dinner in jail, a detail reported by The Oregonian newspaper.
Pedersen said during his statement that nobody takes the "so-called criminal justice system" seriously, and police and prosecutors must be held accountable for their actions in his case. "We all know what to do with me, but what of them?" he said.
As he continued to press the topic and express his views on Israel, drones and torture, his sister, Holly Perez, yelled at him to "shut up." He stopped for a moment and continued for a few more minutes.
Earlier, Perez told the court that Pedersen showed no remorse and sympathy for the victims, and she was glad that he would no longer be able to use the courtroom and the press as his "personal soap box."
"You could at least look at me," she instructed her brother.
U.S. District Judge Ancer Haggerty told the siblings that Pedersen is not required to make eye contact.
Pedersen and Grigsby began their killing spree on Sept. 26, 2011, with the deaths of his father and stepmother, David "Red" Pedersen and Leslie Pedersen. The couple then drove Red Pedersen's vehicle south into Oregon, where they shot and killed 19-year-old Cody Myers and stole his car.
They shot Myers, who was Christian, because his name sounded Jewish, according to court documents.
Pedersen and Grigsby then headed to Northern California, where Reginald Clark, a 53-year-old black man, was shot to death.
Grigsby and Pedersen were arrested Oct. 5, 2011, outside Yuba City, California, when a police officer spotted them in Myers' car. Grigsby told officers they were on their way to Sacramento to "kill more Jews,'" court documents said.