In my country, we use agent status sticker. It allows the police to automatically make arrests of any vagrants that are on the property.
I would look into that to see if you guys have an equivalent.
We use the trespass citation. It’s an official written warning by law enforcement (we usually also snap and print a picture of the person).
If they violate the trespass citation, they are immediately arrested.
The second time that brat and his friends trespassed, they would have been hauled away by police.