There's been a lot of false reports - reporters can't even get which vehicle he drove right -car or truck....let alone how this all unfolded. So it misleads people into thinking what they should not until there's an investigation.
If you watch the video of him entering the school , that's not been slowed down, clearly he “ran” into the school and was on the run. But if you go by the slow downed version it looks like he just walked in. So people get the wrong impressions all the time.
It also didn’t look like he was in a fire fight when he ran into the building. At least in that video
The part that I most DON”T understand is why on Earth the school was not totally locked down immediately once the police were after a known shooter anywhere remotely near the school. My wife teaches at a small private parochial school (two classes per grade level, 30-40 students per grade level). If there is any kind of police pursuit of a dangerous person in the area, the schools (not just my wife’s) are notified and they lock down, with all doors (all pretty substantial, BTW, @ my wife’s school) barred. A shooter “could” get in — if he has a quarter stick of dynamite or equivalent with him/her...
I’m told that it’s 60 seconds max from the time the officer calls in the encounter / chase (etc.) to dispatch, to the time the school is clammed up. And really, properly organized and planned / set up, in 2022 there is no reason it should take any longer.