The FBI says 66-year-old Marc M. Keyser was taken into custody without incidence at his home Wednesday afternoon. He is charged with three counts of sending a hoax letter.
The FBI says Keyser sent over 120 envelopes containing a packet of sugar with the label "Anthrax Sample."
So far the agency says none of the packets have tested positive for hazardous material.
The letters were received Wednesday by two Sacramento television stations, The San Diego Union-Tribune newspaper, The Charlotte Observer newspaper in North Carolina, and the office of Congressman George Radanovich in Modesto.