The suspect arrested for sending ricin-laced letters to Sen. Roger Wicker (R-Miss.) and President Obama was charged with using mail to threaten the president and others.

The suspect, Paul Kevin Curtis of Corinth, Miss., faces as many as 15 years in prison, three years of supervised release and a $500,000 fine under the federal charges, which were announced on Thursday by U.S. Attorney for the Northern District of Mississippi Felicia C. Adams and Daniel McMullen, the FBI special agent in charge of overseeing the case.