Well, in Chicago, they have murdered people for not giving them enough money when panhandling, they have murdered people by setting buildings on fire, etc.
Even though this is a discussion about head injuries from sports, we have a problem with all kinds of mental illness. I do not expect Obamacare to make things better. Over where I live a mentally ill man randomly stabbed a professor and his girlfriend as they walked after a sporting event. The man died from his wounds after trying to fend off the man’s unprovoked attack of his girlfriend. The woman survived her wounds.
Another mentally ill man climbed into a bathroom window half naked and proceeded to rape and stab two women in a horrific two hour attack. One woman lost her life from a stab wound to her heart. The other barely survived.
These mentally ill do not need a gun to take innocent life. Sometimes all it takes is a knockout punch that causes their victim to hit the cement so hard it causes massive bleeding in the brain.
Sometimes they kill by dousing their victim with gasoline and setting them on fire.
As for the players, there seems to be evidence that players are experiencing mental side-effects from the use of performance enhancing steroids. All kinds of death and mayhem can be traced to the use of such drugs. These are self induced mental illnesses (also, just discovered damage to the immune system) that are just as damaging as those blows to the head.