Texas Woman Arrested in Ricin Case After Telling FBI Husband Did it

Federal authorities revealed that they have a woman in Texas who is suspected in participation in the mailing of three letters containing ricin that were sent to New York City Mayor Michael Bloomberg, President Obama and the director of Mayors Against Illegal Guns.

The officials say the woman, known as Shannon Rogers Guess-Richardson, initially called the FBI to claim that her husband, Nathaniel, sent the letters. Authorities stated that their investigation ultimately led them to her, according to NBC News.

Authorities say Richardson was arrested Friday in Arkansas and charges against her are expected to be filed later Friday afternoon.

All three threatening letters were postmarked May 20 and sent without a return address or signature, officials have said.

The text of the mailings threatened: "what's in this letter is nothing compared to what I've got planned for you," police and law enforcement sources said.

The letter addressed to Bloomberg was discovered at City Hall's mail sorting facility at 100 Gold St. on May 24, a law enforcement source told NBC 4 New York. It appeared to contain a pink, oily substance when a mail worker came across it and was immediately flagged as suspicious.

The New York Post reported that another man from Texas was being questioned in connection to the poisoned letters sent to Bloomberg. The man's wife apparently contacted FBI agents after she discovered "Tupperware [container] with what looks like ricin in the refrigerator," a source said, as well as directions on how to make the poison.

The letters sent to Bloomberg were intercepted at a Shreveport, La. mail facility and authorities are treating them as a separate case.

The Centers for Disease Control and Prevention identifies ricin as a poison that is found naturally in castor beans. Affected individuals may experience difficulty with breathing, as well as vomiting and redness of skin.