At least it wasn't an ambush.
Officer stabbed, he shots and kills the person, and they're writing about possible criminal charges? Here is where this is going, and this is how bad it's going to get: There is going to come a time (soon) where police officers are going to have to actually be hit; either be it from a bullet or a edged weapon before they can actually fire back. This is going to result in a massive walk off shortage of LEO's which will result in chaos, and finally, Marshall law. The masses are going to give in to the thug loving protesters.