Graffiti spraying on 100+ year old trees around the park

Students from Highcrest Academy and The Beaconsfield School have spray painted ancient trees in the park and been seen destroying really big trees by pulling down huge branches. I have a couple of times seen students from both these schools spray painting trees that are really old large trees and asked them to stop. I have also seen them pull down a huge branch from a willow tree, the spray painting concerns me as it will never come off. Please can someone contact the schools and ask teachers and parents to check bags of students for spray cans. I have more photos of other trees in the park that have been sprayed too but your photo limit is only 3. The students responsible have also sprayed theirs tag on the side of Winston house on Fennels Road. I have names that other kids have given me of the kids causing the damage. The paint will never come off the trees and I would like to know what the consequences are for the students causing such damage. Kingsmead park is usually well looked after but this has been going on since last March and it needs to stop because it is getting worse. Is it possible to contact the schools and do something about it?