I'm glad they were charged. In my house the 15 year old doesn't have access to the safe. If the parents secured the firearms and ammo and only allowed their kid to use with supervision this could have been prevented. This is a parenting problem. Failure to secure their weapons and inadequate supervision.
The Sandy Hook shooter's mom kept her guns locked in a safe. Her son killed her to get to them. Either he knew the combo without her knowing he did, or he knew where she kept the key. Either way, he gained access in spite of her REASONABLE efforts to prevent it from happening.
So, no! You can't prevent a persistent and resourceful teen from accessing your guns. All it takes is a hidden camera to steal the combo as it's entered or knowing where the combo is written down or the key is kept.
Reasonable doesn't mean totally fool-proof. When the kid lives under the same roof as the safe and the gun owner, it's only a matter of time before they find a way.
This case has to be judged on the specific facts involved. You can't make general statements claiming that all parents can and should prevent their child from accessing their firearms or be thrown in prison. Of course, you already have, huh?
On a side note, throwing a parent or two in prison doesn't prevent anything. They are only charged AFTER their child uses the gun for criminal purposes. That's how laws work. They only punish people after the fact.
Maybe SOME parents will see that as a deterrent and decide to change their ways -- i.e. buying a better safe and keeping the combo private. But not every parent will think that way. As some say, kids may need access to the family firearms in case of emergency. The odds that they will use the gun to commit intentional murder are close to zero.
Next, you'll say we need surprise snap inspections of homes in which anyone owns guns and has kids, just to make sure we are all safe from the kids.
Even if someone has a safe and the kids don't have access, do you really think the parents will never remove the gun and have it out for cleaning, taking to the range, etc.? Opportunities to gain access will present themselves.
Bull hockey.