Using your timeline of mass shooting increases, an immediate reason to consider should be the assault weapon law expiring in 2004. Data would back that up. We haven’t had the same laws forever. https://ohiocapitaljournal.com/2022/06/15/did-the-assault-weapons-ban-of-1994-bring-down-mass-shootings-heres-what-the-data-tells-us/

Firefox on Android used to do this. I switched to Kiwi when they dropped it.