Ricin Letter Sent to Obama: 5 Fast Facts You Need to Know

UPDATE 1:04 p.m.: John McCain’s office reports suspicious letter. Shelby’s office gives all clear.

UPDATE 12:35 p.m.: Here’s the official FBI statement:

UPDATE 12:28 p.m.: Democrat Senator Carl Levin of Michigan makes statement confirming a suspicious letter received at his Saginaw office.

UPDATE 12:17 p.m.: LIVE PRESS CONFERENCE: Jay Carney, White House Press Secretary confirms letter was addressed to the president. The president has been briefed. The letter will be re-tested.

UPDATE 12:12 p.m.: White House press conference set to begin any moment. Was scheduled for 11:45. Here’s the live-stream:

UPDATE 12:08 p.m.: Capitol Hill cops reportedly questioning person who sent two suspicious packages.

UPDATE 12:02 p.m.:

A letter laced with the deadly poison ricin has been intercepted on its way to President Obama. Here’s what we know so far. There will be a press briefing shortly.

1. The Secret Service confirms a letter with a suspicious substance was sent to President Obama. Multiple outlets including the Wall Street Journal report it has tested positive for ricin.

2. This comes a day after Republican Senator Roger Wicker of Mississippi was sent a letter laced with ricin. MEANWHILE, Capital Police are probing a suspicious package at the office Alabama Republican Senator Richard Shelby.

3. Despite this ricin scare’s similarities to the post-9/11 anthrax-letter scare, the “current FBI assessment” is that there’s no link between the letters and the Boston Bombing, reports NBC:

An FBI official told NBC News that the agency did not initially believe the letters were related to the attack on the Boston Marathon on Monday.

4. Ricin is an extremely deadly substance, 1,000 times more deadly than cyanide. It’s made from the castor oil plant. There is no antidote.

5. False-positive tests for ricin do occur. A Homeland Security official told ABC false positives for ricin occur at least once a year. The letter will be re-tested.