The bombs were placed at street level, where they caused mainly severe leg injuries, including numerous amputations. Had they been placed higher, those would have become head injuries and decapitations... in other words scores of deaths.
It was the placement of the bombs that made them less deadly. The triggers and hardware worked reliably, and did show expertise. I'm pretty sure the investigation will turn up that a pro either trained them or handed them the triggers ready made.
It was the placement of the bombs that made them less deadly. The triggers and hardware worked reliably, and did show expertise. I'm pretty sure the investigation will turn up that a pro either trained them or handed them the triggers ready made.
I'd think pro training would have incorporated the vehicle bomb, which is not some kind of technological breakthrough, having been used for a century including during the Wall Street bombing. Does anyone really think bombing a marathon made for bigger headlines than an Oklahoma City-style bombing would have? McVeigh attempted to minimize non-government casualties. If he had chosen a street with buildings on all sides, a thousand people might have died. A Islamist pro isn't going to be worried about these niceties.
On the video and all images I've seen, they looked calm as if they had rehearsed the attack quite a bit or had carried out similar attack(s) in some other part of the world.