[FreeAtlanta]

Surely they won’t blow them all up. I imagine a lot more evidence could be gathered from an unexploded bomb.

[Fred Hayek]

Of course there are fingerprints, if the bombmaker was not careful to cover his tracks. The way the device was constructed can provide other clues - who taught the bombmaker, and thus maybe a trail of breadcrumbs.

[DJlaysitup]

Surely they won’t blow them all up. I imagine a lot more evidence could be gathered from an unexploded bomb.

Exactly...this is just a blind guess, but if there were 5 or 6 devices and only two went off - "they" may have been trying to have "cascading" explosions set off via cell phones. Once the first couple went off everybody would jump on their own phones and clog up the service...effectively saving some lives.

Having the unexploded ones should be serious evidence for inspectors.