Letter Sent to Obama Tests Positive for Ricin

Same sender as letter sent to Sen. Wicker

A letter addressed to President Barack Obama tested positive for the poison ricin and was from the same sender who mailed a letter to a senator that also tested positive, officials told NBC News on Wednesday.

The letter to Obama was intercepted at an off-site White House mail facility Tuesday and was being tested further, a Secret Service official told NBC News. A federal law enforcement official said that the letter was "very similar" to one addressed to Sen. Roger Wicker, R-Miss.