I think we should also seriously consider guards at schools and increased police patrols in malls and places where people gather in large numbers. Another common thread in these shootings is that the shooters keep shooting until they are engaged by police or some other armed person. If they don't burn out first. At that point they surrender or shoot themselves.
I don't think any ban on a particular type of weapon, or size of magazine will be effective. The deadliest shooting in US history, Virginia Tech, was done with a simple 9mm handgun. That is all you need when your alone for several minutes in a building full of unarmed people.