The Prevalence of Mental Illness in America
Mental illness is often used as a red herring for gun control. Mental health is extremely important and worthy of increased funding and attention, but it shouldn't be conflated with lax gun regulations.
https://www.nimh.nih.gov/health/statistics/prevalence/any-mental-illness-ami-among-us-adults.shtml
https://www.nimh.nih.gov/health/statistics/prevalence/any-disorder-among-children.shtml
2nd Amendment
Gun ownership in America
Just 3% of American adults own 50% of all guns.
It's currently against the law for the government to have a searchable database of gun ownership.
Summary - https://www.vice.com/amp/en_us/article/wdbd9y/the-atfs-nonsensical-non-searchable-gun-databases-explained-392
NY Times - http://www.nytimes.com/2012/12/26/us/legislative-handcuffs-limit-atfs-ability-to-fight-gun-crime.html
Wikipedia - https://en.wikipedia.org/wiki/Firearm_Owners_Protection_Act
The CDC (Centers for Disease Control) is forbidden from researching guns as a cause of injury and death by the Dickey Amendment:
Wikipedia - https://en.wikipedia.org/wiki/Dickey_Amendment_(1996)
Mass Shootings -
Washington Post - https://www.washingtonpost.com/graphics/national/mass-shootings-in-america/
Opposition POV -
Guns and Ammo http://www.gunsandammo.com/politics/cdc-gun-research-backfires-on-obama/