This week's arrest of a Mississippi man suspected of mailing ricin to President Obama and other government figures raises the question of why recent use of the highly lethal and relatively easy-to-make poison appears limited to individuals and small groups with colorful political views.
Until he was taken into custody on Wednesday in connection with three mailings of the toxin, Paul Kevin Curtis might have been best known for his performances of songs by Elvis Presley and other rock-and-roll leading lights. The 45-year-old reportedly faced financial struggles, though, and he described an underground market for "dismembered body parts [and] organs" as well as collusion among various law enforcement agencies to undermine his standing "in the country music scene."
The charges, if true, would make Curtis just one of several aspiring ricin attackers. Four elderly militia members were arrested in 2011 after their ruminations about launching an antigovernment ricin attack were overheard at a Waffle House restaurant in Georgia. Las Vegas has contended with multiple ricin cases: a biochemist committed suicide in 2003 by injecting himself with the poison, and authorities seized a quantity of the toxin from a motel room in 2008.
Ricin is most notorious for its use in the murder of Bulgarian dissident Georgi Markov, who died in 1978 after being stabbed with an umbrella tipped with the poison. The castor bean derivative inhibits production of critical proteins in humans and can be lethal in trace amounts. It is most potent when delivered directly into the bloodstream, Scientific American reported.
The Centers for Disease Control and Prevention has described a possibility of introducing a fatal amount of the toxin into the digestive tract or delivering it as an inhalable aerosol. However, no state-run WMD program is believed to have succeeded in manufacturing large batches of the substance for delivery as a weapon.
In the latest case, the FBI said letters containing a "granular substance" that tested positive as ricin were intended to reach Obama, Senator Roger Wicker (R-Miss.) and a Mississippi justice official.
The suspect in the latest mailings appears to have been "a rather uninformed individual" who believed ricin could have been delivered as effectively via the postal system as the anthrax spores mailed to media and government figures in 2001, said Gary Cecchine, who oversees research for the RAND Gulf States Policy Institute.
It would be "pretty hard" to poison someone using mailed ricin, he added. Primate research suggests particles must be around 1-2 microns across to be deliverable through the air; more finely ground ricin would be breathed back out and coarser material could lodge in an air passage before reaching deep inside the body, the Washington Post reported.
"He's probably not unlike some of these other fringe groups that are just chopping up beans and making a lot of noise about it," Cecchine said.
Still, there are "some very sophisticated chemical methods where you can actually extract this particular toxin ... and then refine or mill it in various ways," the expert added. The United States investigated ricin's warfare potential during both world wars and granted a patent for one chemical extraction process in 1962, though the procedure's effectiveness has since come under dispute, he said.
Cecchine termed ricin "a weapon of mass disruption," and noted that mailings of an inert form of the substance in 2004 forced the shutdown of three Senate office buildings but ultimately "didn't hurt anybody."
Ricin has fascinated fringe conservative groups in the United States for the last several decades, said Mark Pitcavage, investigative research director for the Anti-Defamation League. As recipes for the toxin circulate regularly at gun shows and numerous "right-wing places," the potential weapon is likely to occur to individuals harboring malevolent intentions and sympathetic political leanings, he said.