Some people in this thread forget what PTSD actually stands for and what it means. Post-Traumatic Stress Disorder. You know, experiencing stress that simulates a traumatic event that has happened PRIOR.
Loud and sharp noises that simulates gun fire can be debilitating for a combat veteran or veteran officer.
Screaming and crying that simulates dying and injured people for medical personnel.
Screeching of tires or vehicles backfiring that simulates car accidents for people involved in car accidents.
The list goes on and on. Hence why it has a broad range of diagnosis.
The real problem America has isn't a gun control problem, it's a medical problem. Research into a lot of these incidents has nothing to do with how easily available weapons are, because weapons are everywhere. You can make a bomb out of fertilizer, Molotov roostertails at your local gas station, chlorine gas from bleach and vinegar. I'm not denying that we shouldn't have some logically stricter gun control, permits, certifications, etc. But saying that banning guns will solve this problem is only blinding yourself and those around you.
Almost all of these incidents revolve around medical problems, PTSD, mental illnesses, drug abuse. The United States has a poor track record taking care of these problems, rather just stimulating them. Under-funding the VA, Big Pharma, poor care for drug abusers, and a toxic masculinity-feminity (Not some SJW bullstuff, I'm talking about telling boys/girls it's not okay to cry, alpha-male bravado, or ignoring the emotions of boys/girls, or simple neglect.)
When I say almost, it's not just a generalization, some cases were motivated by something else: politics, money, greed.
This particular incident happens to be that of a former Marine with PTSD. A Machine Gunner in the Marines. Infantry jobs in the Marines are very harsh.
Millions of the people in the US own actual fire-arms, yet this country isn't a war zone. Yet millions of people in the US know someone with a debilitating illness and don't help.