Paul Kevin Curtis was accused of using ricin to kill the president in 2013, but it quickly emerged that an associate was the culprit.

The man at the center of it all, Paul Kevin Curtis, an Elvis impersonator, was also accused of sending poisonous letters to President Obama and was arrested for it. However, the police didn't have enough evidence, and he was released. It was later revealed that he was framed by a man he had a long-standing feud with.

Netflix's "The Kings of Tupelo" explains why James Everett Duchtske tried to assassinate Barack Obama with ricin letters in 2013.