Law enforcement

F.B.I. Steps Up Use of Stings in ISIS Cases

The F.B.I. has significantly increased its use of stings in terrorism cases, employing agents and informants to pose as jihadists, bomb makers, gun dealers or online “friends” in hundreds of investigations into Americans suspected of supporting the Islamic State, records and interviews show.

Undercover operations, once seen as a last resort, are now used in about two of every three prosecutions involving people suspected of supporting the Islamic State, a sharp rise in the span of just two years, according to a New York Times analysis. Charges have been brought against nearly 90 Americans believed to be linked to the group.

The increase in the number of these secret operations, which put operatives in the middle of purported plots, has come with little public or congressional scrutiny, and the stings rely on F.B.I. guidelines that predate the rise of the Islamic State.