1. Universal background checks: Please explain how you would implement and enforce that (As of January 1, 2016, only 18 persons had been prosecuted under Colorado's 2013 mandatory law for private sales).
2. 72 Hour waiting periods: Please name one perpetrator who carried out his mass shooting less than 72 hours after acquiring his weapon(s).
3. Purchase limits on ammunition: Please tell us how this will be accomplished. Whether one buys a lot of ammo from a single store, or a little from a lot of stores, there's no effective way to prevent someone from amassing a large quantity of ammunition.
4. Federalizing/standardizing CCW training requirements: Please identify which mass shootings were carried out by CCW permit holders.  Studies have shown that permit holders commit crimes at about the same rate as sworn law enforcement officers.  As a group, they tend to be among the most law abiding people anywhere.