The U.S. Senate sergeant-at-arms says a private lab has confirmed the presence of ricin in a letter sent to Sen. Roger Wicker.
Terrance Gainer said today that the lab tests confirm field testing that indicated the presence of the toxin. He says the ricin, which was found Tuesday at a Maryland mail processing center, was not weaponized.
On Wednesday, the FBI arrested a Mississippi man suspected of sending the letter to Wicker and another to President Barack Obama. Kevin Curtis is expected in federal court later Thursday.
The FBI has not yet reported the results of its testing of the material.