The same people who decide that felons cannot own guns.
Mental health professionals should be required to report anyone who admits to having suicidal tendencies.
You can't ban guns, but I'll bet most parents wouldn't mind seeing a ban on murder-based shoot-em-up video games. Maybe Hollywood movies need a higher standard for violent content....like PG-18.
Each year there are more than 40,000 suicides. Half of them are firearm suicides.