Calling the cops is what happens when a student is so completely defiant and violent that he really needs to be physically handled. Teachers are not legally allowed to do that, but cops can. That’s why the cops are called.
It was very different many years ago
In 1969 I was 11 years old and in sixth grade. We had a problem, Dindu,who had been held back a lot. He was 14 years old. He started acting up in class and our male teacher finally had enough and ordered the student to go to the front office. The student refused and the teacher walked over by the kid. The kid was quite tall and stood up then took a swing at our teacher. The teacher grabbed the kid by his shirt, slammed him against the brick wall and the kid went down like a sack of wet cement.
Out teacher then grabbed the totally stunned kid by his foot and dragged the punk to the front office.
We never saw that kid again and our teacher never got into trouble.