An arrest is clearly overkill. Many urban districts are trying to go against the insanity of the past 20 years of zero tolerance and return the classroom management to the classroom teacher, along with more leeway. That said, like your post, such things are usually a call for help. I have see in kids that I personally have known for many years. I have seen it in kids that I hardly know. Such things almost always a request for a response by the child. It might be dropping everything and having a one on one conversation, or therapy. Some educators think that just ignoring the kid is the proper thing to do, and honestly sometimes it is, and if the behavior is repetitive then it simply a training thing, like the baby repeatedly dropping the spoon. But it is a new things, or an escalating things, while it may not be a plan to actually cause harm to someone or themselves, it could be a cry for abuse or some other such thing. Which, again, is not best handled by calling the cops.
So we have had the conversation, and attention has been given, and I hope you feel better.