May 30th, 2013
11:16 PM ET

Umbrella fired fatal ricin dart

Georgi Markov was on his way to work in London. He felt a sharp pain in the back of his right thigh while waiting for the bus. Gary Tuchman reports on a surprising ricin murder case from the Cold War era.

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Filed under: 360° Radar • Crime • Ricin
May 29th, 2013
10:42 PM ET

Mayor Bloomberg reacts to ricin letters

Preliminary tests indicate ricin was found in letters sent last weekend to New York City Mayor Bloomberg and the director of Mayors Against Illegal Guns. The American Postal Workers Union said the letters were postmarked in Shreveport, Louisiana.

"The letter obviously, referred to our anti-gun efforts but there's 12,000 people (who) are going to get killed this year with guns and 19,000 that are going to commit suicide with guns, and we're not going to walk away from those efforts," Bloomberg said.

There is no known cure for the toxic substance. A small amount can kill a person within 36 to 48 hours.

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Filed under: Michael Bloomberg • Ricin
April 17th, 2013
10:56 PM ET

Ricin as a weapon

Dr. Sanjay Gupta says the process of making ricin is not easy and some types of contact with the compound can be deadly.

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Filed under: Ricin
AC360 411: Ricin’s Wrath
April 17th, 2013
07:18 PM ET

AC360 411: Ricin’s Wrath

Editor’s Note: We’ll have the latest developments on the ricin investigation tonight on AC360° at 8 and 10 p.m. ET.

Suspicious mail laced with ricin has Washington on edge. Preliminary testing shows a letter addressed to Pres. Obama and another to Mississippi Republican Sen. Roger Wicker both tested positive for the poison at off-site mail facilities.

Additional testing on the letters should be complete on Thursday. According to a law enforcement source, both letters had the same message: "To see a wrong and not expose it, is to become a silent partner to its continuance. And the same closing statement: "I am KC and I approve this message." Here’s the AC360° 411 on ricin:


  • If ingested, injected or inhaled, less than a pinpoint can kill a human within 36 to 48 hours.
  • Initial symptoms of ricin poisoning by inhalation may occur as early as 4-8 hours and as late as 24 hours after exposure.
  • If ricin is ingested, initial symptoms typically occur in less than 10 hours.
  • If ingested, ricin causes nausea, vomiting and internal bleeding of the stomach and intestines, followed by failure of the major organs and death usually follows.
  • If injected, ricin causes immediate death to the muscles and lymph nodes near the site of the injection.
  • Ricin is a natural, highly toxic compound extracted from castor beans.
  • Ricin has been used experimentally in medicine to kill cancer cells.
  • There is no known cure for ricin poisoning. FULL POST
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Filed under: AC360° 411 • Ricin