Secret Service official: Letter with suspicious substance sent to Obama

Story by NBC News

A letter addressed to President Barack Obama containing a suspicious substance was received at a White House mail facility and is being tested, a Secret Service official told NBC News on Wednesday.

On Tuesday, the FBI said that a letter intended for Sen. Roger Wicker, R-Miss., had tested positive for ricin, a deadly poison.

The letter was intercepted at a postal facility in Maryland that screens mail sent to Congress, and never reached Wicker’s office. The senator thanked law enforcement and said an investigation was underway but did not elaborate.

Other senators were made aware of the Wicker letter during a briefing Tuesday evening on the bombing at the Boston Marathon. Sen. Claire McCaskill, D-Mo., said that the person who sent Wicker the letter writes often to elected officials.

The Wicker letter was postmarked Memphis, Tenn., and had no return addres.

Ricin poisoning can kill within 36 hours, and there is no antidote.