Shannon Richardson, 35, is charged with two counts of mailing a threatening communication and one count of making a threat against the president of the United States, the US Attorney's Office for the Eastern District of Texas said in a news release on Friday.
"What's in this letter is nothing compared to what I've got in store for you, Mr. President," the letter to Obama said.
Richardson, an actress from Texas, was arrested June 7. She is accused of sending the threatening letters in May to Obama, Michael Bloomberg and a third man who heads the billionaire mayor's gun-control group. Richardson faces up to five years in prison on each of the charges.
The government accused Richardson of mailing the letters and trying to pin the crime on Nathan Richardson, whom she married in 2011. He filed for divorce earlier this month. Authorities have said that the ricin letters threatened violence against gun-control advocates.
According to an FBI affidavit, Shannon Richardson first contacted authorities to implicate her husband in the scheme. But she failed a polygraph exam and investigators found inconsistencies in her story, the document alleges.
Richardson later admitted she mailed the letters but maintained that her husband made her do it, according to the affidavit.
