The Portland case has been held up as an example of how FBI stings can make a terrorist where there might have been only an angry loser. "This is a kid who, it can be reasonably inferred, barely had the capacity to put his shoes on in the morning," Wedick says.
But Tidwell, the retired FBI official, says Mohamud was exactly the kind of person the FBI needs to flush out. "That kid was pretty specific about what he wanted to do," he says. "What would you do in response? Wait for him to figure it out himself? If you'll notice, most of these folks [targeted in stings] plead guilty. They don't say, 'I've been entrapped,' or, 'I was immature.'" That's true—though it's also true that defendants and their attorneys know that the odds of succeeding at trial are vanishingly small. Nearly two-thirds of all terrorism prosecutions since 9/11 have ended in guilty pleas, and experts hypothesize that it's difficult for such defendants to get a fair trial. "The plots people are accused of being part of—attacking subway systems or trying to bomb a building—are so frightening that they can overwhelm a jury," notes David Cole, a Georgetown University law professor who has studied these types of cases.
But the Mohamud story wasn't quite over—it would end up changing the course of another case on the opposite side of the country. In Maryland, rookie FBI agent Keith Bender had been working a sting against 21-year-old Antonio Martinez , a recent convert to Islam who'd posted inflammatory comments on Facebook ("The sword is cummin the reign of oppression is about 2 cease inshallah"). An FBI informant had befriended Martinez and, in recorded conversations, they talked about attacking a military recruiting station.
Just as the sting was building to its climax, Martinez saw news reports about the Mohamud case, and how there was an undercover operative involved. He worried: Was he, too, being lured into a sting? He called his supposed terrorist contact: "I'm not falling for no BS," he told him .
Faced with the risk of losing the target, the informant—whose name is not revealed in court records—met with Martinez and pulled him back into the plot. But while the informant had recorded numerous previous meetings with Martinez, no recording  was made for this key conversation; in affidavits, the FBI blamed a technical glitch. Two weeks later, on December 8, 2010, Martinez parked what he thought was a car bomb in front of a recruitment center and was arrested when he tried to detonate  it.
Frances Townsend, who served as homeland security adviser to President George W. Bush, concedes that missing recordings in terrorism stings seem suspicious. But, she says, it's more common than you might think: "I can't tell you how many times I had FBI agents in front of me and I yelled, 'You have hundreds of hours of recordings, but you didn't record this meeting.' Sometimes, I admit, they might not record something intentionally"—for fear, she says, that the target will notice. "But more often than not, it's a technical issue."
Wedick, the former FBI agent, is less forgiving. "With the technology the FBI now has access to—these small devices that no one would ever suspect are recorders or transmitters—there's no excuse not to tape interactions between the informant and the target," he says. "So why in many of these terrorism stings are meetings not recorded? Because it's convenient for the FBI not to record."
So what really happens as an informant works his target, sometimes over a period of years, and eases him over the line? For the answer to that, consider once more the case of James Cromitie , the Walmart stocker with a hatred of Jews. Cromitie was the ringleader in the much-publicized Bronx synagogue bombing plot that went to trial last year . But a closer look at the record reveals that while Cromitie was no one's idea of a nice guy, whatever leadership existed in the plot emanated from his sharply dressed, smooth-talking friend Maqsood, a.k.a. FBI informant Shahed Hussain.