A Texas actress has been arrested for sending ricin-tainted letters to President Obama and New York City Mayor Michael Bloomberg.
According to court documents, Shannon Richardson initially tried to blame her husband for sending the letters, but a polygraph exam found her to be "deceptive" on the matter.
Her husband has denied involvement in the case and says his wife wanted to end their marriage.
Richardson faces up to 10 years in prison if convicted.
Authorities are testing a letter addressed to the White House for the presence of ricin.
Investigators say the letter is similar to the ricin laced letters sent to New York City Mayor Michael Bloomberg and his anti-gun group.
Our Deb Feyerick is OutFront with more on the investigation.
CNN has learned that a letter addressed to the New York City Mayor Michael Bloomberg contained material that tested positive in preliminary tests for the deadly poison - ricin.
A second letter also tested positive for the substance that was sent to an office in Washington DC that houses "Mayors against Illegal Guns," an organization Bloomberg helps run.
OutFront tonight: CNN's National Security Analyst Fran Townsend and Dr. Ian Lipkin – an epidemiologist and the medical mind behind the movie "Contagion."