Former actress Shannon Richardson admitted on Tuesday to sending ricin-letters to President Barack Obama and New York Mayor Michael Bloomberg. A graduate of AMC's Zombie School, she landed a role as a walker on the hit show "The Walking Dead."

She entered her plea in federal court in Texarkana in Texas. Shannon is charged with possessing and producing a biological poison called ricin, according to reports from the The Hollywood Reporter.

In June, Shannon was arrested after authorities revealed that she tried to frame her husband, Nathan Richardson. He filed for divorce prior to the incident.

Reports state that Shannon mailed three letter from New Boston and later went to the Police and said that her husband was behind the act.

Shannon is the mother of six children and had minor role in the movie "The Blind Side." It was revealed that investigators caught Richardson after finding inconsistencies in her statements. However, it was out in open that she purchased the materials through internet to produce a biological toxin called ricin. It is a deadly poison that can cause respiratory failure when inhaled by a person.

Shannon revealed in a signed plea that she ordered castor beans online and later learned the process of converting them into ricin. She also got a PayPal account, an e-mail id and post office box in the name of Nathan Richardson (husband).

She waited for her husband to go to work on May 20.

"After he left the house, I printed the mailing labels for President Barack Obama, New York City Mayor Michael Bloomberg, and Mark Glaze with The Raben Group," said Shannon.

The letter to President Obama had these words: "What's in this letter is nothing compared to what ive got in store for you mr president."

"You will have to kill me and my family before you get my guns. Anyone wants to come to my house will get shot in the face," read the letter.

Shannon also acted in "The Change-Up," "The Vampire Diaries," and an American Deli Restaurant advertisement.