School shootings in particular are a "new thing" - I'll grant that. But in general gun violence in the US is definitely not a new thing.
EDIT: Also - schools shooting today are actually still "extreme outliers" on the order of the gang violence of the '30s. They're far more common than they should be, but they're still pretty rare given the number of schools in the US.
Are you serious? There are "icons" from that era known for their violence and "spectacle".
Bonnie & Clyde; Baby face Nelson; Al Capone; John Dillenger; Machine Gun Kelly (before his singing career)
FFS - MACHINE GUN KELLY!
These people were horrible and killed a lot of non-gang members.
"Newsreels from the period chronicled the violence. In one from 1931, footage shot in New York shows walls along a city street pockmarked with bullet holes, and the children caught in the crossfire of gang warfare."