After the Fort Hood shootings, folks are wasting no time blaming the gun and ammo. The shooter used the FN FiveseveN, which fires the 5.7X28. The round is basically a glorified .22 magnum. There is an armor piercing variety of the ammo but that is not for sale commercially. Wired has a look at the issue.
If scores of solders were in a disarmed victim zone, you could probably guess that they weren’t all armoured up in bullet-resistant vests (and when seconds count, the civilian police were 3 minutes away)
CBS radio news, the night after the attack, said (after passing through layers of editorial oversight and all those earlier mistakes about Uzis and whatnot) that this semi-automatic pistol was popular with gangs.