PHOENIX -- An Oklahoma man has pleaded not guilty to charges that he mailed an inoperable homemade bomb nearly a year ago to Maricopa County Sheriff Joe Arpaio.
Gregory Lynn Shrader, 55, of Jay, Okla., entered the plea on Friday in federal court in Phoenix.
Investigators said the bomb was discovered in April at a mail collection-box unit in Flagstaff and was made of smokeless powder, wires, a battery and a pressure-release switch attached to its lid.
Authorities eventually determined the bomb was inoperable, though black powder inside the parcel could have exploded or ignited in a flash fire.
Police disabled the bomb.
Authorities said a woman told them that she drove with Shrader to northern Arizona and saw him place the parcel into the mail box wearing surgical-type gloves.