OXFORD, Miss. —
"Any kid that made it through high school science lab is more than equipped to successfully make a poison out of this stuff. Any fool can get recipes off the Internet and figure out how to do it," Cohen said.
Those seeds, which look a bit like coffee beans, are easy to buy online and are grown around the world; they are often used to make medicinal castor oil, among other things. However, using the seeds to make a highly concentrated form of ricin would require laboratory equipment and expertise to extract, said Raymond Zilinskas, a chemical and biological weapons expert.
"It's an elaborate process," he said.
Cohen said ricin is not common because other poisons, such as anti-freeze, can easily be bought at a store. And it's not a weapon of choice for mass casualties because it would need to be eaten or inhaled to be most deadly.
"You can put this stuff in an envelope, but how are you going to get the intended person to inhale or ingest it?" Cohen said.
Authorities say Curtis sent a letter that may have contained ricin to Sadie Holland, a judge who sentenced him to six months in jail in an assault case a decade ago. Holland's son, Democratic Rep. Steve Holland, said Friday that his 80-year-old mother has undergone medical tests and had no signs of poisoning. He said she had done a "smell test" of the threatening letter, telling him it burned her nose a bit.
If swallowed, the poison can in a matter of days shut down the liver and other organs, resulting in death, according to the federal Centers for Disease Control and Prevention. If inhaled, it can cause respiratory failure, among other symptoms. No antidote exists.