From Slate:
The tiny Uvalde school district has its own seven-person force; the 15,000-person city spends 40 percent of its budget on policing, and in 2020, the Uvalde Police Department proudly touted its nine-person SWAT team that was getting to know the layouts of local schools. Not only did the police spend an hour preparing to enter the school on Tuesday, but there was also this, from a fourth grader to local CBS affiliate KENS, presumably about the police’s first attempt to get into the school:
“When the cops came, the cop said: ‘Yell if you need help!’ And one of the persons in my class said ‘help.’ The guy overheard and he came in and shot her,” the boy said.
Each of these failures shows the absurdity of the GOP’s two-pronged policy response to school shootings—armed teachers and more support for law enforcement. (There was also an armed guard at the Buffalo supermarket, for what it’s worth. He fired at the suspect and was killed.) If the town SWAT team can’t stop a school shooter before 19 children are dead, what’s the point? Republicans have since moved on to other innovative proposals, like building schools with only one door, or giving up on schools altogether.
The more I learn about the deliberate inaction of these police, the angrier I get. I am so incandescently angry right now, you may want to stop reading. I’m going to do my best to seethe instead of exploding in a way I’ll regret.

I don’t know if these cops were unable to stop this murderer, because it sure looks like they chose not to try, and the department keeps changing its story to protect them.
An entire classroom was gunned down — 19 children were murdered along with their two heroic teachers who did more than any of these cops to try to protect them — while these fucking cowards tased and handcuffed the parents who were begging these useless men to do their fucking jobs.

What kind of fucked up piece of shit do you have to be to fucking HANDCUFF a parent who is begging you to do your fucking job and save their child’s life WHILE THERE IS AN ACTIVE SHOOTER IN THE CLASSROOM? What kind of fucked up piece of shit do you have to be to use a TASER on a parent who is begging you to do SOMETHING to save their child’s life? What kind of monster does that? I’ll tell you: A piece of shit who isn’t a cop to serve the public, that’s who.
Stop telling me I’m supposed to blindly support cops no matter what. Stop pretending your Blue Lives Matter shit isn’t just a racist dogwhistle. This doesn’t happen when people become cops to protect and serve the public. This is what happens when people become cops so they can bully and harass people with impunity. These cowards aren’t going to risk their lives for anyone. This police force gets FORTY PERCENT of the city’s budget. This tiny town has a SWAT team. That wasn’t enough to save these children and their teachers.

What’s the point of pouring endless money and weapons of war into civilian police forces if they consistently fail to protect the communities who are funding them? I think we all know the answer.
This. Right here. This is a HUGE part of the reason Repugs don't care about school shootings. "Giving up on schools altogether" is a basic plank in the platform of a significant portion of the Religious Reich. At least public schools anyhow. DeVoss was just the tip of the iceberg.
Another reason they don't care of course is that it isn't THEIR kids getting shot. THEY don't go to public schools.