An Illinois man has been arrested and charged with mailing letters containing a white powder to multiple members of Congress, including representatives from the state of Illinois. The suspect, identified as Matthew Unglesbee from Quincy, allegedly used his own return address on the envelopes, raising suspicions and drawing the attention of federal authorities. The letters reportedly included threatening messages along with the white substance, which was stated to resemble anthrax. This series of incidents has prompted additional scrutiny and increased security measures around congressional offices, as similar suspicious letters were sent to other lawmakers in the area.