I do not have well-organized thoughts on this topic. Mostly grief during days like today, and then a sense of confusion about what policy changes would be effective.
Anyway...here in MD, a deep blue state where we had a school incident during our recent legislative session, a bill passed to target the "red flag" matter. (We already have pretty strict gun laws here, but did also just pass a ban on bump stocks) If you're a republican running for the state legislature this year, you can now count on this bill being a centerpiece of the debate about whether you are conservative enough to serve. A few otherwise good and effective legislators are likely to lose their seats over being willing to support a bill trying to act on "red flags" to prevent groups of people from getting/keeping guns.
Here's some online stuff about it, for a flavor.