Beginning in 1991, four members of the "Patriots Council," a Minnesota tax protest group, began to develop a castor-bean derivative known as "ricin," which is one of the most toxic known substances. The members involved learned the process of manufacturing ricin from a mail-order pamphlet. The group planned to suspend the substance in a toxic gel capable of transmission through a skin barrier, and then to place the impregnated gel on doorknobs, handles, and steering wheels. They were considering whether to target IRS agents, U.S. Marshals, or local sheriffs for ricin attacks when the FBI arrested them.
In 1993, Thomas Lavy attempted to cross the Canadian border carrying 130 grams of ricin -- an amount that, if administered in individual doses, would be sufficient to kill over 32,000 people -- as well as four guns and $89,000 in cash. Canadian officials returned Lavy to the United States because of the amount of cash he was carrying. A search of Lavy's cabin by law enforcement officers revealed that he possessed mail-order books, such as The Poisoner's Handbook, Silent Death, and Get Even: The Complete Book of Dirty Tricks, which, among other things, describe how to make and use ricin. Lavy committed suicide before he could be tried.