@stux speaking as someone who literally despises the NRA, saying only 6% of the mass shootings having an armed individual to stop the shooter in response to someone saying we need more individuals armed to stop shootings is not nearly the gotcha that you think it is. Its essentially saying, "you think we need more people with guns to stop mass shooters? Well I'll have you know there's almost nobody out there with a gun to stop mass shooters! Checkmate, republicans!" Deeply stupid.
Secondly, the question of gun control is WAY more complicated in America than folks across the pond think it is, considering that minorities are frisked and generally affected at significantly higher rates than white people. Many of the gun control laws in effect now were also enacted by none other than Ronald Reagan to curb Black Panther groups and keep majority-black neighborhoods from being able to keep themselves safe.
Tldr, you don't know what you're talking about. Please stop.