Updated 9:15 a.m. Sunday: Dutschke was charged on Saturday with "developing ... and possessing" ricin and "attempting" to use it "as a weapon," according to a joint statement by the U.S. attorney for the northern district of Mississippi and FBI's Mississippi office chief, Reuters reports. If convicted, he faces maximum possible penalties of life in prison and a fine of $250,000. 

Original post: A Mississippi martial arts instructor named Everett Dutschke, 41, was arrested by U.S. Marshals early Saturday morning and taken into custody in connection with several letters containing the deadly chemical ricin that were sent to U.S. President Barack Obama and two other U.S. lawmakers last week, a local Mississippi police chief told Reuters.

Dutschke's home and former business are being searched. It is not immediately known whether he has been charged, nor was any motive apparent.

FBI agents and U.S. Capital Police had previously searched Dutschke's home on Tuesday and Wednesday, and they set up surveillance on his home on Friday before moving in to arrest him on Saturday around 1 a.m. EDT, Reuters said.

Elvis impersonator Paul Kevin Curtis, 45, was originally taken in for questioning and charged in the ricin incidents, but those charges were dropped on Tuesday.

Besides Obama, the two other lawmakers targeted were Mississippi Republican Senator Roger Wicker, and Mississippi State Judge Sadie Holland, who is 80 years old, the AP reported

Dutschke, who teaches tae kwon do in Tupelo, Miss., is also the subject of a current child molestation investigation, USA Today reported, in which he is maintaining his innocence.

Dutschke's name came up earlier in the week, prompting the original search of his home, before police dropped their charges against Curtis. In a phone conversation with the AP while his house was being searched the first time, Dutschke said, "I'm a patriotic American. I don't have any grudges against anybody. I did not send the letters." 

Curtis was under investigation because the letters addressed to Obama and Wicker were both signed "I am KC and I approve this message," a signature similar to one used by Kevin Curtis when he had previously sent letters to Wicker and other lawmakers, the A.P. said. Dutschke and Curtis reportedly met once in 2005 but did not get along. 

Ricin is a highly toxic protein that comes from certain castor oil plants. A very small amount can kill an adult, even when inhaled.