Evidence is emerging that the crazed attacker may have used an "assault knife" with a high capacity blade...
(don't be fooled by the bright cheerful color...this is a death dealing device with no other legitimate purpose.)
...and that he paused between stabbings to break off the used blade so that he would have a fresh blade available for the next victim. Police say that if only the perpetrator had had to take the time to pull out a whetstone and sharpen between stabbings the body count would have been much lower. Obviously, these high capacity "assault knives" will need to be regulated. Perhaps a three or five blade capacity would have dramatically lowered the number of victims before the perpetrator could be stopped. California is looking at legislation that will prevent all knives from actually being sharpened with the exception of those used by law enforcement.
There is also evidence to suggest that this knife may have been one of the extremely dangerous "imported assault knives" perhaps from Eastern Europe or even Asia. Import restrictions on these weapons of death and destruction (they are no good for anything else) need to be put in place immediately. Of course, we would then be facing the illicit trade in black market "assault knives" which are assembled from "parts" and sold without any background check at all at "knife shows."
Registration for all knife owners may be the answer to this problem but there will almost certainly be cries from right wingers about how that will not stop criminals who don't obey the law anyway.
Thank goodness he didn't have one of those "black knives" that are so scary and inflict so much damage...
(shown without the collapsible stock, pistol grip and scope...features that proponents frequently add to their "sporting knives.")