House Acts in Wake of Blackwater Incident

Why did take the unprovoked killing of unarmed Iraqis to get this done? Why weren't Blackwater* and the other mercenaries already under the jurisdiction of U.S. courts?

I already knew they weren't, but it never made sense to me.

Prompted by last month's deadly shootings in Baghdad by armed guards working for Blackwater USA, the House voted overwhelmingly yesterday to place all private contractors working in Iraq and other combat zones under the jurisdiction of U.S. courts.

Via WaPo.

*To be fair, the mercenaries are only accused at this point.