A 36-year-old former actress from Texas pleaded guilty Tuesday to mailing ricin-laced letters to President Barack Obama, New York Mayor Michael Bloomberg and a gun control advocate, the Associated Press reported.

Shannon Guess Richardson admitted to a federal charge of possessing and producing a biological toxin during a court appearance in Texarkana, Texas following her arrest in June.

Ricin is a biological toxin that can be fatal if ingested, inhaled, or injected. There's no known antidote or cure for ricin poisoning.

"Shannon is anxious to admit her role in ordering the components to make the ricin, her role in the letters that contained the ricin, and to tell the government who else was involved in those offenses," Tonda Curry, Richardson's attorney told the AP.

Richardson was apprehended earlier this year after authorities said she tried to accuse her ex-husband, Nathan Richardson, of sending the toxic agent to the political officials after he filed for divorce, the AP reported.

A statement from the United States Attorney's Office in Texas, said Richardson mailed the threatening letters to Obama, Bloomberg and gun-control advocate Mark Glaze in Washington D.C. from New Boston outside of Texarkana on May 20. Ten days later, she traveled to the Shreveport, La. Police Department and claimed her husband was responsible for the ricin-laced letters.

Prosecutors told the AP that investigators noticed inconsistencies in Richardson's statements and later learned she'd purchased materials online to produce ricin, a biological toxin that can cause respiratory failure if inhaled.

Agence France-Presse reported that the letter sent to Bloomberg read: "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 ... The right to bear arms is my constitutional God given right and I will exercise that right till the day I die. What's in this letter is nothing compared to what I've got planned for you."

The AP reported that the letter addressed to Obama was akin to the one sent to Bloomberg: "What's in this letter is nothing compared to what I've got in store for you Mr. President."

Richardson faces up to a life in prison for the offenses.

The former actress had minor roles in the television series "The Walking Dead" and the movie "The Blind Side." She also is the mother of six children - including one child born prematurely while she was in custody this year.

A federal judge will sentence Richardson at a later sentencing hearing, which has not yet been scheduled.