Colorado man faces prison over anthrax hoax

A Colorado man faces up to five years in prison and a $250,000 fine for lying to federal investigators about mailing threatening letters to tax collectors in the state that contained a white powder.

Matthew O'Neill pled guilty to the charges, which stem from an incident in 2011 in which a mail room employee received a legal-sized manila envelope that contained an unidentified white powder. The letter was mailed to the Colorado Department of Revenue and included post marks for Kremmling, Colo., Government Security News reports.

The employee and a co-worker contacted the Colorado State Patrol and 911 and waited for the Hazmat and Denver Fire Department teams to arrive. The teams evacuated the building and tested the substance, finding it to be harmless baking soda.

According to the letter's intended recipient, O'Neill had previously sent documents expressing beliefs that he doesn't have to pay federal or state taxes as a sovereign citizen. Postal inspectors and the FBI determined that O'Neill had visited the Kremmling post office several days before the envelope arrived.

"Those who mail a threat, especially one containing material simulating a biological or chemical agent, will face felony criminal consequences," John Walsh, the U.S. attorney, said, according to Government Security News.

While the powder was not harmful, threatening mailings count as a federal crime.

"All threatening communications are taken seriously, the recipient of these types of threats cannot determine the true nature of the implied, or stated danger," James Yacone, the FBI Denver special agent in charge, said, according to Government Security News. "The FBI wants to remind everyone that mailing a threatening communication that contains a hoax of any kind in a parcel will be aggressively investigated. We will continue to respond to such threats, along with our federal, state, and local law enforcement partners, through the combined resources of the Joint Terrorism Task Force."