I would like to add the fact that it does not take much skill to hurt, seriously injure, or even kill someone with a knife. The weapon is not just a tactical variable. Like all weapons, the knife increases one's defensive and offensive ability - greatly. Thus, for example, one serious kick-ass martial artist, with loads of expertise in loads of knife-disarming/control techniques, even one that trains in knife fighting, has seriously got his/her hands full when facing some idiot with a knife that just starts stabbing and slashing all over the place as fast as they can.
For example, while I do not advocate kicking as THE solution, and while we should note the crazy limiting factor of "being in an elevator," etc., we can see how full one's hands would be by watching the first part of this video:
Yeah, Chuck, that is how those pics came my way, but even then, I was a little suspicious as to the type of the wounds manifested in light of the modern types of body armor that is now worn in most places. So, I wasn't too surprised either after I did some research on the story. Nevertheless, as I said, as you said, the pics still show the issue at hand, whatever their specific scenario.