PORTLAND, Ore. (AP) — An Oregon man pleaded not guilty Friday to charges that he assaulted a federal officer by detonating an explosive as the officer approached his vehicle to make an arrest.

Jason Schaefer, 26, lost several fingers in the Oct. 11 explosion and his left hand was heavily wrapped at his arraignment in Portland.

An FBI agent wrote in an affidavit that Schaefer yelled to police who pulled him over that everyone was going to die, and then triggered the blast by holding a lighter to a cigarette packet that contained an unspecified explosive material.

The affidavit says a Washington County detective working as part of the federal Joint Terrorism Task Force suffered ringing in his ears, and was hit with glass from Schaefer's SUV and the flesh from Schaefer's mangled left hand. The detective returned to work after five days.

Authorities had been monitoring Schaefer since at least September, concerned that the felon on probation for possessing body armor had purchased explosives. The detective had tried to make the arrest at Schaefer's suburban Portland apartment complex, but the suspect ran to his car and drove away — leading to the explosive traffic stop.

Assistant U.S. Attorney Craig Gabriel said authorities found a package in Schaefer's damaged car that contained TATP, an explosive that's been used in several overseas terrorist attacks. Packages with the same explosive were also found at Schaefer's storage locker.

Sgt. Steve Collins, a Portland police bomb technician, said the peroxide-based explosive is commonly known on the Internet and can be made from household ingredients.

"It can kill you," he said. "It's very dangerous stuff; it's very dangerous to make, it's very dangerous to handle."

No terrorism charges have been filed. U.S. Attorney for Oregon Billy Williams and Renn Cannon, the special agent in charge of the Portland office of the FBI, declined to speculate on why Schaefer had explosives or what his intentions might have been.

"It is important to stress that at this time we believe there is no further threat to the public safety," Williams said.

Schaefer was sentenced to probation in May after pleading guilty to being a felon in possession of body armor. In 2011, he was convicted in New York of second-degree assault.

In requesting Schaefer's continued detainment, Gabriel said Schaefer made a threatening remark at the jail when complaining about inadequate pain medication for his hand. "I'm obliged to see your death," Gabriel quoted Schaefer as writing to a doctor.

Schaefer's attorney, Mark Ahlemeyer, said he has not received discovery material from the investigation and can't comment on the allegations.

Judge Stacie Beckerman scheduled a four-day trial to begin Dec. 27. Schaefer remains in jail.

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