That suggests the intent of such incarceration is deterrence. If not that, what?
And if that, does it work?
Deterrence means preventing future repetitions.
But incarceration in this case does not do that, since he has no other sons he could buy a rifle for.
Instead this takes a grieving father and increases his pain, for no reason.
And that just increases the spiral of violence.
Making a foolish mistake is not the same as having harmful intent.
This makes the legal system an extension of personal vengence.