The Indianapolis killer as far as we know to date was not driven by any white supremacy beliefs (much to the sadness of the progressives), but instead was apparently well known to be CCFCP*
Indeed, he was even "known to the FBI" which as Cindy at From the Caer has rightly commented, is about the most useless titles for a potential mass-killer. Apparently, "known to the FBI" means the FBI makes sure it will stay well out of your way until you commit a mass killing and then say "yep, we knew him".
Verily, this fellow and the action taken by police in response to his being CCFCP* and proclaiming he wanted to commit suicide by cop was indeed the very example of the glaring failure and obvious inherent flaw of Red Flag laws:
The Detroit News: Prosecutor: FedEx shooter didn’t have ‘red flag’ hearing
Authorities believed they had done what they
needed to by seizing the pump-action shotgun from Brandon Scott Hole in
March 2020, Marion County Prosecutor Ryan Mears said.
“Absolutely
there needs to be some intervention and absolutely the firearm needs to
be taken away. … But the risk is if we move forward with that (red
flag) process and lose, we have to give that firearm back to that
person,” Mears said. “That’s not something we were willing to do.”
The shotgun was never returned to Hole, police have said.
Read that one again. He was reported to be likely to kill others and himself, the police responded by taking a firearm away and then not even holding a "Red Flag hearing" because they might have lost and had to return it.
So they did what everyone who has concerns about red flag laws has pointed out as to what can occur: They left him free to go out and purchase another firearm and commit murder, and he did.
But hey, at least they thought they did what they needed to do.
Yep, take the firearm away from the madman and leave the madman free and unsupervised to go forth and commit mayhem - including going out and buying another gun, explosive, gasoline, what have you.
A rather glaring and fundamental flaw in the whole process.
Now, had they taken him in under a psych hold it would have gone differently. If he was then involuntarily committed as a threat to himself or others - which sounds pretty darn likely - then after a hearing (with all that due process stuff the anti-gunners don't like, which is why they circumvent it to go with a red flag law), he would have been designated in NICS and been unable to legally purchase a firearm. Even more importantly, he would have received treatment for his underlying psychosis of being CCFCP.* These involuntary commitment laws predate red flags and are a lot more effective. But the police and other officials need to actually decide to use them.
But, that was too much work apparently, and the police apparently figured that just partially red flagging him instead of having him get treatment for his underlying mental instability would suffice.
It obviously did not.
Red Flag Laws don't prevent an act of mass murder, they just delay it a bit.
* CCFCP for those who don't know means Coo Coo For Cocoa Puffs. Since we don't know the wackjob's actual diagnosis, that will have to suffice.