One immature nut bag taints all gun owners in the same way the alleged actions of a small group of ironworkers is used to beat on all union members.
Dunn, 47, has earned our loathing and a possible 70 years in jail for three counts of attempted murder - even without a verdict for shooting Davis. There's little chance he'll walk free.
The facts in the case (with echoes of George Zimmerman and Trayvon Martin): Davis and three friends, all African-American, were in an SUV playing loud music at a Jacksonville gas station. Dunn asked (or demanded) they turn it down. Davis and Dunn argued. Davis cursed Dunn, who said he saw a shotgun. Dunn pulled a 9 mm handgun and fired 10 times at the SUV, then drove away. Davis was killed.
Cops found no gun.
The Internet - part wonderland, part petting zoo, part insane asylum - exploded with theories, most involving race.
Someone said an infuriated Dunn lashed out because a rising tide of minorities threaten his status in America. Loss of so-called "white privilege" pulled the trigger?
What motivated Davis? Dunn acted like a master on a plantation, someone theorized, and the 17-year-old was tired of being "oppressed." This is based on no evidence, but it could be true.
So could this: It was generational. In a similar case, Curtis Reeves, a 71-year-old trigger-happy ex-cop shot Chad Oulson, 43, in a suburban Tampa movie theater after he and the younger man, both white, exchanged words and Oulson threw popcorn at Reeves.
Each shooter was old enough to be the victim's father and it was a younger dude getting mouthy with an elder, not showing deference and respect.
Florida has a controversial "stand your ground" law, which means if you feel threatened with harm or worse, you can shoot. Although that defense was not used in the Zimmerman and Dunn cases, that mind-set permeated them.
In 2011, Pennsylvania changed its self-defense statute to something similar, allowing lethal force if a person "believes that such force is immediately necessary" for protection.
When I got my first gun I did some reading because guns are dangerous and I am not an idiot. I wondered why Pennsylvania didn't test me, as it does car drivers, for proficiency and knowledge of the law. If "testing" isn't constitutional, then at least instructing me. (I got my first gun because my life had been threatened. Job-related, it happens to some reporters.)
Back then, in Pennsylvania, if I was confronted with a threat I was obliged to retreat, if possible. I could fire only if I have no alternative. Today, I have no obligation to retreat, but I still would - and have (as unmanly as it may seem). Why? I don't want to deal with the burden of wounding or killing someone - in terms of time, legal fees and possible psychological damage to myself.
I will use lethal force only to protect myself or loved ones from actual, imminent, serious harm.
A loud car radio isn't that and neither is popcorn in a theater.
The vast majority of gun owners, rational and trustworthy, understand that. Dunn and Reese did not.
On Twitter: @StuBykofsky