If he had only "failed to prevent his kid from shooting up a school" he wouldn't have even been charged with anything.
The law - in practice - is heavily weighted towards giving corporations a pass for criminal behaviour.
If the behaviour is really egregious and lobbying is light really bad cases may lead to changes in regulation.
But generally the worst that happens is a corporation can be sued for harm in a civil suit and penalties are purely financial.
You see this over and over in finance. Banks are regularly pulled up for fraud, insider dealing, money laundering, and so on. Individuals - mostly low/mid ranking - sometimes go to jail. But banks as a whole are hardly ever shut down, and the worst offenders almost never make any serious effort to clean up their culture.
This seems ass backwards