For starters, get rid of school boards. Next, mandatory retirement for school officials at age 29. Seriously. There are too many people running schools who are just too lazy or out of touch to deal with analyzing situations to determine whether there is anything worth bothering about. A zero tolerance policy means that you don't have to do anything or make any judgement calls because the policy does it for you. "Our hands are tied!" "There is nothing we can do!" "We have a zero tolerance policy!" It removes them from any of the responsibility of decision-making. Honestly, elementary school children have more sense and maturity than most of the dweebs running the schools.
Um, wow. I work in a district with a zero tolerance policy. It is not enforced in grade schools, unless there is a battery involved. In middle school and high school it is different for any weapon. Now we don't have the thing with the aspirin and other OTC drugs.
I would say start with the superintendent and the school board. Principals have considerable lee way in what the pass up the line and how they deal with it. There is still quite a bit of interpretation of policy that occurs, especially when it comes to student to student violence. Both of the grade schools and the middle school I worked at had a fair amount of student violence.
At the grade school level a fist being thrown may or may not result in suspension, much less an expulsion hearing. Usually the students involved have to show a repeated pattern of battery. In the middle and high schools the scenario matters a lot, who threw the first punch and who stopped when staff arrived. I saw students get one day suspensions when they instigated the fight and the other get ten days because when staff arrived they knocked the other student down and kicked them in the face.
The only crash landing in a knife or gun at middle school or high school. And not a plastic knife either. Now shivs will also get you a crash landing.
Staff involvement is another issue, I was assaulted by a student how made a very poor choice and deliberately caused me harm. My principal asked me if I was going to push for expulsion, i said no. It was a stupid choice on the students part, I did have a huge bruise. Now other staff made poor choices and then pressed for expulsion, which by policy is a factor. But putting your self in harms way is stupid and then punishing the student for it is also stupid.
Now part of what makes it work in our district is school resource officers and station adjustment. If what the student did is serious, they are charged with a crime, if they are on probation or delayed sentencing that have to meet with the SRO at the station for weekly meetings. That straightens some of them up.