While I agree with many of your points about lax gun culture in the United States, your conclusion that he will get a " multi-million dollar book and movie combo deal for the story of his life" is a shrill comment that is ignorant of American jurisprudence. Most states and the Federal government have laws that prevent criminals in the United States from profiting from crimes. Although these laws are challenged periodically, they still have legal enforcement for the time being. Realistically, this young man will soon be on death row if found mentally competent (not doing a multi-state book deal as you've suggested). Good op pieces can be completely undone by shallow and lazy conclusions, I would caution against this in future writings.
India hangs only man sentenced to die for 1993 Mumbai blasts (AP)
from the article: Mass, random shooting sprees are as American as baseball and apple pie