TEXARKANA, Texas » A pregnant Texas actress who first told the FBI that her husband sent ricin-tainted letters to President Barack Obama and New York City Mayor Michael Bloomberg, then allegedly said she sent them because her husband “made her” do it, was charged today with threatening the president.

Shannon Guess Richardson, 35, appeared in a Texarkana courtroom after being charged with mailing a threatening communication to the president. The federal charge carries up to 10 years in prison, U.S. attorney’s office spokeswoman Davilyn Walston said.

Richardson, a mother of five who has played bit roles on television and in movies, was arrested earlier Friday for allegedly mailing the ricin-laced letters last month to the White House, Bloomberg and the mayor’s Washington gun-control group. The letters — which authorities determined were mailed from Richardson’s hometown of New Boston and postmarked in Shreveport, La. — threatened violence against gun-control advocates, authorities said.

Her court-appointed attorney didn’t immediately return a message seeking comment.

According to an FBI affidavit, Richardson contacted authorities on May 30 to implicate her estranged husband, Nathaniel Richardson. She later failed a polygraph test, and investigators looking into her story found numerous inconsistencies, the document said.

Among the inconsistencies: Nathaniel Richardson would have been at work at a time when Internet searches tied to the letters were made on the couple’s laptop and at the time they were postmarked.

During an interview with authorities Thursday, Shannon Richardson admitted mailing the letters knowing they contained ricin, but she said her husband had typed them and made her print and send them, the affidavit said.

No charges have been filed against Nathaniel Richardson. His attorney, John Delk, told The Associated Press today that his client was pleased with his wife’s arrest and was working with authorities to prove his innocence.

Delk said he wasn’t anticipating that Nathanial Richardson would be arrested. “But until I’m sure they’re not looking at him being involved, I can’t say much more,” he said.

Delk previously told the AP that the couple is going through a divorce and that the 33-year-old Army veteran may have been “set up” by his wife.

FBI agents wearing hazardous material suits were seen going in and out of the Richardsons’ house on Wednesday in nearby New Boston, about 150 miles northeast of Dallas near the Arkansas and Oklahoma borders. Authorities conducted a similar search on May 31.

The house is now under quarantine for “environmental or toxic agents,” according to a posting at the residence. Multiple samples taken from the couples’ home tested positive for ricin, according to the affidavit. Federal agents also found castor beans — the key ingredient in ricin — along with syringes and other items that could be used to extract the lethal poison, the affidavit says.

Multiple samples taken from the couple’s home tested positive for ricin, according to the affidavit.

Bloomberg issued a statement today thanking local and federal law enforcement agencies “for their outstanding work in apprehending a suspect,” saying they worked collaboratively from the outset “and will continue to do so as the investigation continues.”

Shannon Richardson appears in movies and on TV under the name Shannon Guess. Her resume on the Internet movie database IMDb said she has had small television roles in “The Vampire Diaries” and “The Walking Dead.” She had a minor role in the movie “The Blind Side” and appeared in an Avis commercial, according to the resume.

She was seen leaving a Texarkana hospital today shortly before the court hearing, though it was unclear why she was there. A hospital spokeswoman didn’t return a phone message seeking comment.

Delk said the Richardsons were expecting their first child in October. Shannon Richardson also has five children ranging in age from 4 to 19 from other relationships, four of whom had been living with the couple in the New Boston home, the attorney said.

Nathaniel Richardson works as a mechanic at the Red River Army Depot in Texarkana, Texas, a facility that repairs tanks, Humvees and other mobile military equipment. He and Shannon were married in October 2011.

According to court records, Shannon Richardson is in federal custody. The government is requesting that she be held without bond, and a detention hearing is scheduled for next Friday, the records show.

The FBI is investigating at least three cases over the past two months in which ricin was mailed to Obama and other public figures. Ricin has been sent to officials sporadically over the years, but experts say that there seems to be a recent uptick and that copycat attacks — made possible by the relative ease of extracting the poison — may be the reason.

If inhaled, ricin can cause respiratory failure, among other symptoms. If swallowed, it can shut down the liver and other organs, resulting in death. The amount of ricin that can fit on the head of a pin is said to be enough to kill an adult if properly prepared. No antidote is available, though researchers are trying to develop one.

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