At 20 years old, had the firearm been locked away, I have zero doubt that the young man would not have access to it.
Some people are born with bad traits, nothing can change that, I am speaking from personal experience.
At that, nowadays, they are not subject to rules and regulations we had aa children and young adults, snot faced punks, from an early age are allowed to , or even encouraged to be the the little asses they are.