Way back in the 70's there was a movie "RollerBall" starring James Caan. The intro "Toccata and Fugue in D-minor" theme music really inspired me, not to mention James Caan and John Houseman's performance... And the F1 style themes (Gladiators to battle)
Rollerball (the movie) was inspired by a short story by William Harrison titled "Rollerball Murder (1973)".
Not sure of the behind the scenes moves but after Rollerball came out, a set of William Harrison's short stories were published under the Rollerball title. The first of which is a short story titled "The Warrior (1971)". Harrison tells the story in an odd way - the reader is included in the story, as if you/me the reader is present with our host. That makes it 2nd person? Anyway. tl;dr version our host is a hardened mercenary of many battles and feels the need to school the free spirits at the film festival on the beach that the world is a terrible place. By shooting up the festival in a fairly graphic manor.
And he even observes at first I won't even have to worry about them running because they won't believe their eyes! IIRC some at first thought the bullet reports were just fireworks.
And includes a detailed plan to escaping the scene to
I have read stuff that falls into a category of "Dang, I wish I'd written that". Not often but it happens. This falls into the penultimate "I never could have conceived of this in a million years". Same same for the LV killer.
I have no idea whatsoever if any of this applies to the LV killer. There has been no information of any military service for the LV Killer, but there are parallels. Just relatin' stuff I've read.
Sorry for the delay, it's taken some time to find my copy and reread the story... It's been at least 30 years. BTW, my copy was almost certainly obtained at the local SVDP for a dime.