He passed a background check last year to become a naturalized citizen, which means one of two things. Either the background check ain’t much of a check — Fox notes that “the process does not look in depth at foreign or domestic travel” — or this guy became radicalized only very recently. A true lone-wolf jihadi acting on a sudden surge of fanaticism would be awfully tough to stop.

But this guy isn’t a lone wolf.

Times Square bombing suspect Faisal Shahzad told interrogators that he received training in bomb making during a recent five-month trip to Pakistan, according to a senior U.S. official familiar with the matter.

The official said Mr. Shahzad received his training in the tribal region of Waziristan bordering the Afghan border…

Pakistan police have detained at least four people in connection with the investigation, Pakistani intelligence sources said. The suspects, who were not named and have not been charged, were picked up in a raid on Gulshan-E-Iqbal, a suburb of Karachi.

Mr. Shahzad was born in Karachi and left at an unspecified date for the U.S., Pakistan police and intelligence sources said. He appears to have traveled back to Karachi for several visits, including one between July and August last year. During that trip he also visited Peshawar, a gateway town to the tribal regions where the Taliban have found refuge in recent years.

A Pakistani official confirmed to Time magazine that he was at a camp and that he had ties with “militants.” The money question: What should we make of the fact that his bomb wasn’t very good? Possibilities: (a) Shahzad’s an idiot; (b) Shahzad’s not an idiot but all the skilled bomb-makers in Waziristan have been zapped by U.S. drones; (c) Shahzad couldn’t get hold of the parts he wanted/needed, like explosive fertilizer, thanks to federal regs; (d) Shahzad could have gotten hold of what he needed if he’d had more time, but this was a rush job to avenge the deaths of the AQI jihadis in Iraq. A former agent with the ATF told the Times that the bomb looked like a “Rube Goldberg contraption,” but Shahzad seems to have known what he was doing in one respect: The parts he bought were all available in grocery and hardware stores, and therefore avoided detection by merchants trained to recognize possible terrorism-related purchases (e.g., dealers in ammonium nitrate). Another odd wrinkle to all this is why Shahzad chose a time bomb instead of a suicide attack, which would have given him more control over the outcome. That’s not unprecedented (remember, the car bombs found around London three years ago were all set to be remotely detonated), and it could be as simple as him not wanting to leave his wife and kids without a provider. But I wonder if jihadis are now having a hard enough time getting people into the country that they’re reluctant to part with even one of them in a kaboom. A good sign, if so.

What’s not a good sign, as Thomas Joscelyn notes, is that this is the third attack in eight months that either came off successfully or failed only because of the bomber’s own incompetence. Hasan did what he set out to do and Abdulmutallab would have succeeded had his bomb been built a little better. There were major intel failures in those cases but I’m not sure if there’s one here — yet. Apart from profiling any young male who spends several months in Pakistan incommunicado — and after the Zazi plot and those five Americans arrested in Pakistan last year, maybe that’ll soon be on the table — there are no obvious solutions I’ve heard of thus far vis-a-vis catching a guy like Shahzad before he acts. The biggest intel bungle to date, in fact, was letting him get on the plane last night despite his having been added to the no-fly list earlier in the day. How’d that happen? Apparently, customs only checks people’s documents on their way into the U.S., not on their way out. That loophole will likely be closed now, but beyond that, I’m not sure what anyone was supposed to have done differently. Although I sure would like some further details on CBS’s claim yesterday that Shahzad’s name was “familiar” to counterterror officials…