"Their" father is Aaron Brink, former MMA hopeful and pornographic film performer.
That's be enough to put anyone in a mental hurt locker. "They" were a ticking time bomb that they system failed and failed to prevent him from hurting others.
No amount of gun control laws would have prevented it. Case in point, his "AR style" rifle was a ghost gun. Remember when Uncle Joe took a victory lap after signing a law that would prevent those? Yeah, that was great.