The gun violence, not all of it can be avoided, but deaths in domestic violence situations can, if Americans don't have such easy access to guns, as I said it only takes one moment of anger, someone threatens another with a gun, gun goes off, person dead. More survived being threatened by a knife than a gun, also outside of domestic violence situations, there are heaps of drive-bys and mass shootings in the USA, way more compared to Australia.
So something needs to be done, as even a semi-automatic gun can do a lot of damage in a short time, even gangs fighting with pistols can do a lot in a short time...
Also kids taking guns to school is not on.... Nor teachers, it just goes back to, too much damage can be done in a short time in a moment of anger, where as a knife can be stopped quickly with less chance of someone dying, or way less people dying.