Some people simply aren’t intelligent enough to own firearms. Sadly, it always seems that someone else has to pay for their stupidity, and this time, it was a nine-year-old boy innocently playing video games who was executed by a two-year-old thanks to the idiocy and careless gun-handling of their mother.

A 9-year-old boy shot in the head by his 2-year-old brother with their mother’s handgun died Tuesday, and their mother told police she had previously let the toddler handle the gun when it wasn’t loaded, authorities said.

Landen Lavarnia was declared dead at a hospital, Phoenix police spokesman Sgt. Vince Lewis said. Police had initially said the boy died on Monday when he was shot. But they corrected themselves and said he remained on life support earlier Tuesday before dying in the late afternoon.

The mother, Wendy Lavarnia, 28, told police she had put her loaded gun on a bed within reach of her 2-year-old and 4-year-old sons while she turned to get a holster, according to court records. That’s when the 2-year-old grabbed the gun and shot her 9-year-old son, who was playing video games a few feet away, police said.

Wendy Lavarnia told police she had allowed “the 2-year-old to practice pulling the trigger of this gun when empty on previous occasions,” the records showed.

Lavarnia had appeared in court briefly before the boy was declared dead, and asked the judge whether she could go to the hospital to see him, but the judge said she couldn’t get out of jail without posting a $25,000 bond. The judge also said she had to stay away from victims in the case as well as any children.

She didn’t have an attorney and spoke little during her brief appearance. She was jailed on suspicion of four counts of child abuse – one count for each of her four children in the home.

Lavernia essentially programmed her toddler to shoot a firearm when he was far too young and mentally immature to have any idea of the consequences of firing a weapon. She then placed the loaded and unsecured weapon within the child’s reach. Is it any surprise at all that this kid did precisely what his mother trained him to do?

This is part of the reason why I cringe when I hear well-intentioned gun owners who insist that merely training a child how to use firearms is “enough,” and that they don’t need to lock up their guns.

Put bluntly, that’s a steaming pile of crap.

No matter how well your drill your child or teach them the rules of gun safety, they are not truly “safe” around firearms without direct adult supervision. From a biological perspective, children lack judgement and discernment because their brains aren’t fully developed. They act more out of emotion than rational thought processes.

It doesn’t matter how smart teens are or how well they scored on the SAT or ACT. Good judgment isn’t something they can excel in, at least not yet.

The rational part of a teen’s brain isn’t fully developed and won’t be until age 25 or so.

In fact, recent research has found that adult and teen brains work differently. Adults think with the prefrontal cortex, the brain’s rational part. This is the part of the brain that responds to situations with good judgment and an awareness of long-term consequences. Teens process information with the amygdala. This is the emotional part.

In teen’s brains, the connections between the emotional part of the brain and the decision-making center are still developing—and not necessarily at the same rate. That’s why when teens experience overwhelming emotional input, they can’t explain later what they were thinking.

They weren’t thinking as much as they were feeling.

Our kids aren’t stupid. They simply lack good judgement. They’re not biologically equipped for it yet, and it only comes with maturity. Our job is to get them their safely.

One way to ensure that they get there is to keep firearms that are not under our direct control locked up at all times.

Small children such as this toddler simply don’t understand what’s going on, and even with fresh safety training in their minds, many will touch or pick up a firearm within their reach if they think an adult isn’t watching. Teens, God bless them, are erratic in their own way as they wage an internal war that pits rational thought versus hormones versus social chaos. They can get very irrational and act rashly. We see teen suicides and homicides and “accidents” with firearms every single week.

The common denominator in all of these instances is the same: a child had access to a firearm when not under direct adult supervision.

The solution is the same: lock up your guns when not under your direct control.

Don’t get me wrong. I think safety training is imperative, and my daughters (one teen, and one in elementary school) know the safety rules by heart. The older one is even a pretty decent shot with a rifle, when she’s in the mood to go to the range.

But I’ve been in this field for too long, and have seen too many stories and back-stories to ever leave a gun out where they could touch it. It’s on me, or locked away. I don’t put them in high cabinets, in drawers, on closet shelves, or under the bed. They go on my body, or in the safe.

If all parents did the same, all the time, do you know how many stories we’d cover like this?

Zero.

I, for one, would be perfectly content to never write another story like this again.

How about you?