Small town, small town cops, little experience with explosives, no military or police bomb experts nearby, a guy who sat through a couple of classes a few years ago....

I've handled explosives and booby traps (as we called them then). I would no more pick one up than I'd jump of house and try to fly south for the winter.

None of use know enough about the construction of the device (and the police aren't telling) to make an intelligent comment.

How much explosive was there? What kind? Was anything such as nails or rocks used for shrapnel? Were there any anti-lift or anti-movement devices? Was it radio or cell phone detonated? Was the first bomb a dud that failed in its job to bring a lot of first responders to the scene so the second could take them out? What was the motivation of the guy who built it (a "person of interest" is in police custody)?

Right now we just don't know enough to do more than guess.