We can fix most mass shootings by fixing the underlying economic issues, which also ties into racial and gender issues. Like, gang violence isn't happening in a vacuum; you largely don't see gang violence in middle-income neighborhoods and towns. You don't even see that level of violence in poverty-stricken rural areas; it's mostly when you pack masses of people together and they're all desperately competing for the same necessary resources. Many of the "solutions" end up not being solutions at all. Take, for instance, education. The education system in the US has eroded sharply, and the trend has been to create charter and magnet schools to give parents "more choices". But those choice reduce diversity, and leave the worst performing students behind, and also siphon money away from public schools, which further reduces education quality. Or public housing in Chicago; it was build, and then promptly packed with poverty and then allowed to fester for 40 years until conditions were so bad that they had to demolish everything.

No one wants to spend the money to fix the problem; everyone wants to pay lower taxes and then complain.

Broadly speaking, I tend to look towards a more socialist solution to the issues; higher taxes, but particularly bringing marginal tax rates back to pre-1970 levels. There's a lot of shit that needs to be done to fix problems, and a lot of it wouldn't be popular since people want bread and circuses rather than putting in work.

Fixing the far-right that have been using mass-shootings as a form of terrorism hoping to spark a race war is much, much more challenging, since that's related to phantom issues rather than rooted in reality.