No, not ignore it, but try to understand why it happened.
1. It wasn't because of lax gun control, and the AR ban would not have prevented it.
2. Just like Dylan Roof killing blacks in church...
3. Or the guy killing Jews in their Pittsburgh Synagogue...
4. Or the guy in Norway killing 77 people...
en.wikipedia.org
5. If we had "red flag" Laws where the government could track all of your posts, and interview your contacts, and have A.I. update police you are violent and then they can take your guns away, especially in big cities where gangs would be prime targets of government tracking and interdiction, would you support that?
5. Similarly, the government could track violent "white supremacists" and disarm them, okay?
I'd bet that the gang bangers would lose a lot more guns than the white-supremacists.