The "American Heritage Dictionary" defines a weapon of mass destruction as: "a weapon that can cause widespread destruction or kill large numbers of people, especially a nuclear, chemical, or biological weapon." In other words, it does not have to be nuclear, biological or chemical (NBC). For example, Dzhokhar Tsarnaev, one of the perpetrators of the Boston Marathon bombing, was charged under United States law 18 U.S.C. 2332A for using a weapon of mass destruction and that was a pressure cooker bomb. In other words, it was a weapon that caused large-scale death and destruction, without being an NBC weapon.