Unions don't let their members cross into other union's practice areas!
It’s not a union thing. I was a LEO for 30 years and the school system dumped more and more issues they handled in the past on the PD. My PD didn’t belong to a union either. They don’t want to deal with parents and the threats of lawsuits or other retaliations so they call the cops. The cops have to respond to calls for service. If the cops fail to take action the school complains and when they do take action the parents complain. Most public schools, at least in the area where I worked, didn’t even want cops on their campuses until an issue like this arose where they were more than happy to dump it on the police. These cops were flat out wrong if they did what they were accused of. I’m not making excuses for their actions but this type of issue was always in the past handled by the parents and school. There is absolutely nothing the police can do in this situation based on the age of the children involved.