Such people may have also tried to control these same impulses through the use of mind-altering medications. It could be of intense interest to them to deflect any interest in this topic or investigation in this direction, for this might take away from them this attempt at self-restraint. Again, seen in this light, a noble impulse.
But there can be unintended consequences to this.
That psych drugs don't really work as hoped is long past being proven. It doesn't take specialized knowledge to know that drugs, any drugs, often reverse their effects over time; this same effect has been seen with psychiatric medications -- with violent consequences. Even the drug companies have found a 'lack of effectiveness' in many medications, and have stopped manufacturing them in some cases. Whether this is an attempt to forestall class-action lawsuits which must of necessity arise attendant to any investigation into the connection between psychiatric medications and shootings can only be guessed at.
It's not that complicated a guess.
I would also like to suggest that any gun control legislation outright ban the ownership of guns by ANYONE on psychiatric medication. This would include the military and police forces -- no guns for anyone on psych meds, ever, period. If decent law-abiding citizens can't be trusted with guns, then those with a history of psychiatric treatment requiring medication can't be either.
And then watch to see who opposes that.
It's also not surprising that the government is doing what they're doing about all this. It isn't like they suddenly got smart about something...remember the economy?