@Billyblobber
Both Dylan Roof and this latest nutcase could have sought help. They chose not to.
Lots of people, sane or otherwise, get fired from their jobs.
Even mentally ill people must take at least some responsibility for their actions.
"Responsibility for their actions" does nothing to fix the core problems. Focusing on punishment is basically a religious/Bible viewpoint that takes any pressure for helping to fix the issues in the world out of the individual while placing wrongdoers in a separate "other" category that removes any relation to them. "The evil must be punished for being evil, don't worry about anything else, God will fix all the problems in the world in the end" is what many people were brought up, and it translates now into them focusing on retribution instead of solving.
A big part of Root's issue was that his particular brand of issues found a nurturing environment in extreme right wing and racist communities and ideology that festers among the Internet. This one is tied into the media glorification and focus on spree killers. Both of these things can actually be addressed and mitigated to a degree to lower the chances of similar things happening in the future. We can also address the lack of mental health system, help people to recognize possible issues before they crop out, and lower the stigmatism around mental health problems. It would be NICE to also be able to address the gun society in America, but, unfortunately, that has become so politicized that anything realistic happening is practically impossible at this point. Those are the things you focus on if you actually want to help fix the situation as opposed to making oneself feel better, which is all things like "pay for their actions" accomplishes.