“Anyone too dangerous to own a gun is too dangerous to walk free”
That’s probably not true... I wouldn’t give a firearm to a minor, nor would you give one to an autistic person.
Minors and autistic people don't "walk free". They are under legal guardianship of their parents or some other responsible adult. I also don't think there are many gun dealers that sell firearms to minors or people with autistic. A person too dangerous to own a firearm would be able to bypass the honest gun dealers. That is why they are too dangerous to walk free.