Killing them all now would not be a good idea. Let’s have a very public trial with public execution in HD for good TV viewing.
That would be wonderful, but it’s not going to happen, either in France or here (Tsarnaev). However, maybe the French can get some information and other contacts out of them.
Trial? Why, so they can tell the world about how they’re going to kill all the infidels before the charges are dismissed?