( 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 . The former NFL player was found not guilty of murder and manslaughter charges last month after he shot his girlfriend to death during an argument over her drug use. She had minor roles in `` The Walking Dead '' and `` The Vampire Diaries ''