How many of the terrorism convictions since September 11, 2001 have been the product of entrapment? Some scholars and journalists have suggested that the number is quite high. One report went so far as to claim that only 1% of terrorism prosecutions involve “real” terrorism. The government’s defenders, at the opposite extreme, come close to saying that entrapment in a terrorism case is a contradiction in terms.

Little empirical basis exists for evaluating these competing claims. Existing literature on terrorism and entrapment is typically based on detailed discussions of a few egregious cases, rather than systematic analysis of the phenomenon. Yet estimating the prevalence of entrapment is critical for evaluating the ethics and effectiveness of contemporary counterterrorism policies.

This Article remedies this dearth of information by creating and analyzing a database of terrorism prosecutions since 9/11 (n=580), and coding each of the cases involving an informant (n=317) for twenty indicators of potential entrapment. An analysis of the database reveals that entrapment indicators are widespread among terrorism cases, and that the most serious cases, involving specific plots to commit attacks, have significantly more indicators. Cases with several indicators account for a sizable proportion of all cases, especially among alleged cases of jihadi and left-wing terrorism. These results show that facts and allegations supporting an entrapment defense are not confined to a small number of cases, but rather are quite widespread in post-9/11 terrorism cases.

The Article also examines the suggestion by a journalist that only 1% of terrorism cases have represented a real security threat. It estimates that the proportion of terrorism prosecutions likely to have thwarted genuine terrorism threats is somewhat higher, though still small—about 9% of all jihadi cases and 5% of jihadi cases involving informants.

In light of these findings, the Article recommends that authorities rethink current counterterrorism strategies, concentrating on passive surveillance instead of attempts to coax law-abiding Muslims into terrorist schemes, and shifting more resources toward preventing right-wing terrorism. Finally, the Article proposes reforms that would require the government to have a reasonable suspicion of criminal activity before inducing a suspect into committing a crime, and that would base the entrapment defense on the defendant’s realistic likelihood of committing an offense without government prompting.