What they didn’t know could fill a body bag what they should have done out of extreme care and prudence would be to simply check the disturbed kids back pack for anything that might bring harm to him or others. Drugs, knives, guns, box cutter, etc etc
Why bother having any laws if said laws do not automatically and immediately stop crime?
Right?
Question: Did he have his backpack with him when he went into the bathroom empty handed, then came out armed?
That didn’t stop the killings, so obviously a useless law that should be repealed.
I agree.
But other laws also need to be rigorously enforced.
I am tired of pols and libs yammering about passing more laws when the ones on the books aren’t being adequately enforced.
Felons caught with firearms rarely get anywhere near the time they should. And they almost never get prosecuted federally.
People who cannot possess a firearm yet still try to buy one only get turned away when they fail the Brady. Why aren’t they prosecuted?
Straw buyers who knowingly supply guns to those who can’t legally have them almost never get hit with the full penalties.
Those are but just 3 but they are three of the most important. Can we start actually enforcing laws before we go passing more?
My 14-year-old was hauled into the office and all but cavity-searched because he jokingly typed “I stab you” in a chat (in the school’s forum 
) about who could solve a physics problem faster. I got called in to take him home. He was pretty shaken and learned a good lesson about appropriate online behavior.
Entirely appropriate on the school’s part IMO.
This does not answer all of your questions but it answers some of them. Ethan was definitely on the school’s radar.
When asked to take their child home for the rest of the day, Throne said the student’s parents “flatly refused,” leaving their son behind to “return to work.” And because the student had no prior disciplinary actions on his record, school counselors decided to allow him to return to his class, rather than send him to what they thought would be an empty home, Throne explained.
https://www.cnn.com/2021/12/05/us/michigan-oxford-high-school-shooting-sunday/index.html
This is heartbreaking. They were probably worried he’d kill himself if left alone, and furious the parents didn’t care.
We still don’t know if the parents lied about access to a firearm, or if the school asked.
I agree.
Reading the article ISTM the school was very conscientious and doing their job properly. They were aware of this kid, they were assessing the issue, they got the parents involved, made well reasoned judgements and so on. Hopefully they will not get in trouble for this. They cannot operate like every kid is a mass murderer about to happen (although that may be where we are headed with our schools).
The failure here was on these parents.
Unless the parents said "yes, we have guns at home, " which I doubt. If they knew he had access to a gun, they should have searched his bag. But if the parents were all “Us, guns? Oh no. We would never have a gun in the house”? At that point, this is a disturbed kid with fantasies, not a weapon about to explode.
We’ve had previous threads where gun owners have absolutely bristled at the prospect of even being asked about guns in the home by their pediatricians. Obviously this is a bit different given the warning signs but I can’t imagine anyone was eager to jump into that shark filled pool.
Is it just guns we should be concerned about? A disturbed kid nonetheless can harm himself or others with any number of illicit items he may have in his backpack. A simple search of his backpack to keep him safe should have occurred especially since they ordered him to a psyche evaluation. Risk assessment should include a search of backpack and locker don’t you think so? Boggles the mind that some think the administrators did all that was necessary in that moment.
Please do enumerate the possible items that can fit into a standard backpack that can allow the wielder to pick off half a dozen people from a hundred feet away. Go ahead, I’ll wait.
What’s wrong with looking in his backpack for anything that could inflict harm? Or reveal more evidence of his intentions? You don’t send a suicidal kid away without making sure he’s safe.
A couple of pipe bombs comes to mind. 
Some rat poison to pour on the salad bar or a hot lunch warming tray.
Who knows what some sick bastard is going to do. It’s the item we don’t expect that will kills us best.
Is there a problem with concentrating on guns for now, or do we have to cover all the bases at once? Lowering the risk is not as good solving the problem entirely, but it is certainly better than not lowering the risk at all, wouldn’t you say?
So we can either give up, or we can spent the entire school day with kids standing in line waiting for their packs and persons to be thoroughly searched for anything that might cause harm?
Yes there’s a problem if you think that a highly disturbed kid with violent fantasies and documented cries for help that catch the attention of more than one educator is only a capable of harm if they have access to a gun.
Can you think of no others scenarios where harm could have occurred to him or others absent a gun?
There are protocols for this sort of thing. I don’t think any of them involve searching bags. Maybe they should. I suspect after this, they will. But from what I have heard, I am 90% sure my campus would have handled this the same.