To begin with, I hear he's an atheist. Do the atheists want to own up? Are you prepared to accept your culpability in this crime? I doubt it. Why would you? You would probably retort:
A) who says he's an atheist?Quite so. However, in this case the killer is being associated with people with whom he has no more connection than in the example above. The case is being used to feed the rhetoric about 'domestic extremists', and attack the First and Second Amendments.
B) Even if he is, so what? That's nothing to do with me. Just because he came to a similar conclusion on a particular question, does not implicate me in his crime.
On both of these latter, there can be no compromise. Freedom of speech stays. Liberty to keep and bear arms stays. Not everyone will see it that way, and I doubt if I can convince them out of their position.