A woman pleaded guilty Tuesday to sending ricin-laced letters to U.S. President Barack Obama and New York City mayor Michael Bloomberg at a court in the U.S. state of Texas, local media reported. Shannon Guess Richardson, an actress and mother-of-six, admitted in court to possessing and producing a biological toxin as accused by prosecutors, newspaper Houston Chronicle reported on its website. She acknowledged that she ordered castor beans online and learned how to process them into a substance used to make ricin, and also obtained an email address, a online shopping account and a post office box in her husband's name without his knowledge, according to the report. Richardson, 35, was arrested in June after she allegedly sent the letters not only to Obama and Bloomberg, but to the New York mayor's Washington gun-control group, the report said, before trying to implicate her husband, who has not been charged. The content of the letters is believed to be threat of violence against gun-control advocates, authorities said. A date for sentencing has not yet been given.