Dialogue in the heat of passion, especially pertaining to guns, often produces irrational calls for action that do not address an effective solution.
The seriousness of these shooting tragedies warrants discussion now, but in a rational manner in order to have meaningful results.
You are focusing all the attention on guns and gun laws. This takes away from the importance of the "reason and prevention" aspect that must be studied. That is paramount to finding a solution, if there is one.
The thought that banning a gun will solve the problem of people committing atrocities is delusional and only gives some people a false sense of security.
The attention given to those committing atrocities may also be a factor in others of unstable mind committing an atrocity.
Many of the perpetrators committing atrocities were recognized at a very young age as having severe mental problems. Perhaps an early positive intervention would have had a different outcome in their lives.
George A. Herman