The husband of the actress accused of mailing letters laced with ricin to U.S. President Barack Obama has filed for divorce.

Texas-based Shannon Rogers Richardson was taken into custody by police last week (09Jun13) over allegations she sent three poisonous notes to Obama and New York City Mayor Michael Bloomberg, threatening harm if they continued to push for tougher gun control laws.

The actress, who had bit parts in U.S. Tv shows The Walking Dead and The Vampire Diaries, originally claimed her estranged husband, Nathaniel Richardson, was responsible for the crime, and now he has filed papers to end their nearly two-year marriage.

Shannon Rogers, who is pregnant with Nathaniel's baby, has five other children from previous relationships. She is now facing up to 10 years behind bars after being charged with mailing a threatening communication to the President.