Illinois man accused of threatening Congress with white substances in letters marked with his return address

An Illinois man was charged with two felonies Monday after allegedly sending letters containing an unknown white powder substance to members of Congress, according to a criminal complaint.

Matthew G. Unglesbee was charged with false information and hoaxes and mailing threatening communications after four members of Congress received the letters, which were marked with his return address, according to the complaint.

Unglesbee told the FBI the substance in the letters was salt and that he mailed them as a joke, the complaint read.