I still say the oxymoronic 'zero tolerance' applied in this incident has done far more harm than good. When I send my kids off to school, I expect them to be taught how to think - not what - and for the learning to take place in a supportive, respectful environment. If all that's going to happen is they be told to sit down, shut up, and repeat after me, or we're calling the cops, then we're done. If this were my child in that situation, their last day of school was yesterday.
Special needs children don't have many options. So, the parent may well be forced to utilize this particular campus. My problem with all of it is the school initiated the whole thing, escorted her in and then charged her with a crime for a formality that staff didn't think was important to do at the time, and forbade her from filling in the form when they realized what has transpired. Entrapment.
The school does not define the trespass law. The state legislature and courts do that. Eviction procedures for people who were previously invited onto the property are different than for those who were not invited. It is really not hard to understand.
The teacher calling the parent to come down to calm the child was the right thing to do. The school however broke their own rules and protocol by buzzing her in without having her "sign the book". The principal showed an amazing lack of adaptive flexibility in calling the police and making it an immediate arrest situation without speaking to everyone involved. The first mistake...was really the only critical one. As "stupid" as it sounds, that the parent wasn't allowed to retro-actively sign in, there might simply be automatic protocols in place. In other words...unregistered adult within the building...call the police. And as inflexible and "stupid" as that sounds? In this day and age, it might be the safest protocol to follow.