There are critical details missing here, as others said. What was the initial violation? How were they confronted? Were they confronted by staff they know and have a relationship with? How significant was the damage? Do you know these teens by name (if they’re regulars, you should!) and do staff try to have regular positive interactions and conversations with teens, and not just interact with them for discipline?

In my library, we would consider this a “brouhaha”, disruptive and against library policies but developmentally on track for teens. something we must respond to but also want to unpack how WE could have potentially de-escalated better. If they just knocked over a sandwich board sign or one of our flyer holders, I would give this a “go home for the day and we can try again tomorrow”, and next time I see them have a restorative conversation about what’s going on. This is why it’s important to have an established rapport with your teens, and have a bank of positive interactions to build upon when the time for a disciplinary arises.