MOSCOW, December 11 (RAPSI) - Shannon Richardson, a former actress known for a role in popular TV series Walking Dead, pleaded guilty Tuesday to sending letters with ricin to US President Barack Obama and New York Mayor Michael Bloomberg, CBS reported.

According to prosecutors in the case, Richardson pleaded guilty to possession and production of biological toxin. The plea was made under a deal, which would limit her sentence to 18 years in prison. She could have faced life sentence.

Prosecutors say that originally Richardson tried to implicate her now-estranged husband, NathanRichardson, in the case. However, officials behind the case found inconsistencies in her story. FBI affidavit has also said that Richardson failed a polygraph test as well.

According to BBC, letters with ricin were mailed to three politicians: President Barack Obama, Mayor Michael Bloomberg, who is known for his pro-gun control beliefs, and to Mark Glaze, head of gun control advocacy group Mayors Against Illegal Arms.

The BBC quoted a federal indictment as having said that one letter to Obama read: "What's in this letter is nothing compared to what ive got in store for you mr president."
Ricin is a highly toxic a highly toxic protein obtained from the pressed seeds of the castor oil plant.