( CNN ) -- A federal judge ordered a mental evaluation for a Texas actress charged with sending ricin-tainted letters to President Barack Obama and New York City Mayor Michael Bloomberg last month . Shannon Richardson , 35 , was ordered to undergo the evaluation within 30 days , according to court documents filed in U.S. District Court in Texarkana . She is charged with mailing a threatening communication to the president and faces up to 10 years in prison if convicted . The request was made by Richardson 's attorney . Richardson is in federal custody . Richardson , also known as Shannon Rogers and Shannon Guess , initially told the FBI that her husband , Nathaniel , had sent the ricin-laced letters , but a polygraph exam found her to be `` deceptive '' on the matter , authorities said . Investigators found that her computer storage devices contained the text of threatening letters sent to the president , but the couple 's computer records show her husband could n't have printed them out because he was at work at the time , an FBI arrest affidavit said . Richardson later told investigators she mailed the ricin-tainted letters , but she claimed that her husband typed the letters and forced her to print and mail them , the affidavit said . New poison letters put ricin under microscope . Her husband denied involvement and claimed his wife wanted to end their marriage and leave him , the affidavit said . He told investigators that his wife was `` intentionally misleading '' them , the court papers said . Nathaniel Richardson filed for divorce last week . His wife is pregnant , according to divorce papers . In a statement earlier this month to E ! News , Shannon Richardson said : `` I really ca n't say much at all , but the accusation could n't be further from the truth . '' Richardson has had minor roles in TV series , including `` The Walking Dead '' and `` The Vampire Diaries . '' CNN 's Brian Carberry and Belle Reynoso contributed to this report .
A judge has ordered Shannon Richardson undergo a mental evaluation in 30 days . Richardson is in federal custody , accused of mailing ricin-tainted letters to Obama , Bloomberg . She had minor roles in `` The Walking Dead '' and `` The Vampire Diaries ''