Nobody likes it when people with the same affiliations/demographics as theirs publicly does things they and everyone else would object to. That is something everyone here with an interest in Buddhism has to accept, as well as people with mental illness. It happened, those things are who the shooter is.
In reading the scriptures, there are two kinds of mistakes:
One mistake is to cling to the literal text and miss the inner principles.
The second mistake is to recognize the principles but not apply them to your own mind, so that you waste time and just make them into causes of entanglement.