Here's a question that I haven't seen a lot of speculation on. These two young men were able to make at least 3, and likely more, homemade bombs that all went off as designed. Judging by the ineffectiveness of other bombmakers (unibomber took a little while to figure it out, the guy who tried to blow up Times Square got it wrong, and others), that's a pretty good record. So, where'd he get this expertise from? Or did he have the expertise? I'm a smart guy, and a smart guy who worked with explosives (in a limited capacity)...I don't think I could have pulled it off, or would have without a few test shots. Even military grade stuff doesn't always work as desired.