Exactly, dude, I don't know you. All I know is some legal gun owners commit murder, no way to tell which ones or how many. ... So, safer to assume you're one of the murderers. Unless you'd care to prove you're not by taking a test.
What Mike doesn't take into account is all of the criminals currently posessing firearms. If they've used a firearm to commit a crime, they've already shown a willingness to harm someone for ill with a firearm. If I use a firearm, it is for sport or only to defend my life & property. Also, while I am not a doctor of neither psychology or psychiatry, can't murder be a rational premeditated decision? How do you test for that? Or how about a crime of passion in the heat of the moment? Mike Summitt doesn't have any formal education in those fields either.
h/t to Joe for pointing me at this.