"...The 29-year-old Moroccan was allegedly determined to cause as much damage as possible. But he was arrested before he left a parking garage. His "weapons" had been rendered inoperable. One companion was an undercover agent with the Federal Bureau of Investigation. The other was a paid informer.
Mr El Khalifi's intentions seem clear, and he is currently in prison awaiting trial.
But the question of whether the US government engaged in entrapment - inducing someone to commit a crime he would otherwise not have committed - hovers over cases such as his.
Rather than looking for real plots being hatched, critics say, the FBI is targeting the weak and vulnerable, often in America's Muslim communities. Sometimes those efforts are led by informers, some receiving as much as US$100,000 (Dh367,000) for their efforts.
It is, according to James Wedick, a former FBI agent, "bureau theatre". The FBI, he said, is providing "foolhardy people" all the necessary tools to become bombers and "calling that a case and telling the American public they should feel safe now".
Mr Wedick, who has served as a consultant for the defence in several of these cases, criticised the heavy reliance on paid informants. [Read More]
"Since September 11 it's almost as if the bureau has lost its mind," said Mr Wedick. "We didn't do that before. We didn't send informants into neighbourhoods, looking for people who might be annoyed and then suggest they could become a bomber."
But claiming entrapment is rarely successful as a legal defence. Defendants rest their case on convincing a jury that they would not have committed the offence without the intervention of law enforcement, which is "extremely difficult" to do, said David Cole, a law professor at Georgetown University in Washington.
The bigger the crime, he said, the harder it is to successfully claim entrapment.
"If you think what you are strapping is a suicide bomb to yourself and you go out to do something, it's hard to persuade a jury that you weren't pre-disposed." [Read More]
Mr Cole said law enforcement agencies were under "tremendous pressure" to prevent incidents. But the sheer number of such cases implied, he said, either "very good police work" or "crime that would never have occurred had the government not induced it. I'm confident that in some instances that's the case."
Andrea Prasow, the senior counter-terrorism counsel with Human Rights Watch, said the real issue is how targets are selected.
"Are they actually going after people who they believe are going to commit crimes? Or are they finding people who are angry and providing the impetus, assistance, support for such an attack? And are they doing so based on race or religion?"
In general, Mr Wedick said he believed only a handful of the sting operations since 2001 were "real terrorism cases". One day, he said, "the bureau will see that these cases are at least unethical, and may be illegal"..." [Read More]