Allow private citizens to purchase high power firearms but have them only able to store them at a public and secure location monitored my law enforcement but manage by law bidding citizens.
Establish a black book for arms dealers, any cot dealing to wrong people get excommunicate from the whole community of gun owners and dealers
Pay incentive to proper conduct individuals and those helping catch those guys who break the law, post names and photos all over the US
Give power to the ATF Agency. To the extreme, no one should be able to escape their grasp.
Equip teachers with tazers, stun guns and pepper spray, bean bag guns or rubber bullet guns, instead of REAL GUNS.
Kevlar curtains near doors of schools, design desks to be stackable, Kevlar blankets, and communication channels in class