Dee's article "The Nihilism of the Mass Shooter" (written in 2022, even) (https://default.blog/p/the-nihilism-of-the-mass-shooter) provides more specifics than the generalities in this op-ed. I'm a regular reader, so it's easy for me to see, but I believe that her passion about investigating and reporting on these things is visible even to a new reader. It's clear to me that she actually spends time looking at the sources, e.g. there's a link in the article to one of her sources, a pdf of the law enforcement report on a shooter from Parkland.
More broadly, I'm concerned that the civilization glue of community continues to be in retreat, lack of uniform mental healthcare and healthcare, and lack of reasonable bounds on who can/'t have firearms with similar respect as vehicular operation.
While that means I'm concerned about the same loser types Columbine that continue to be a problem (as mentioned), but I'm also concerned about organized domestic and international terrorists (including accelerationist, race-oriented, and religious groups) out to do much greater harm in ways that aren't just mass shootings.
Also, AI chatbots opens up the potential of automating sentiment manipulation through astroturfing leading towards radicalization goals.
Final qualitative observation: Functional, healthy civilizations seem to produce far fewer revenge-suicide events per capita per time interval.