After a letter laden with the toxic chemical ricin was intercepted yesterday, bound for Senator Roger Wicker, two more letters have tested positive for the substance at offsite mail facilities. The letters that were caught today were addressed to President Obama and Senator Carl Levin's Saginaw office in addition to another letter caught at an offsite government mail facility headed towards the US Senate.

The FBI reported today that filters at the mail facility detected the presence of ricin and that samples were being sent to a laboratory for extensive testing. In attacks that are reminiscent of the Anthrax scare in the wake of the September 11th terrorist attacks politicians are, yet again, targets of bioterrorism.

Ricin is a chemical purified from castor oil beans and is harmful when it is injected or is inhaled. The symptoms are difficulty breathing, fever, nausea, and coughing, profuse sweating, fluid buildup in lungs and possible respiratory failure. Unlike anthrax, ricin is not a living spore that infects people and requires antibiotics. Ricin is a chemical that shuts down protein production in every cell of the body essentially preventing the cell from working properly.

The systems installed in governmental offsite mail facilities after the anthrax attacks following 9/11 were key in detecting the substance before letters made their way to government offices.

After a briefing on the Boston Marathon bombing and about the ricin tainted letter Tuesday Senator Claire McCaskill, said "The person that is a suspect writes a lot of letters to members."