Don't hold your breath over finding the culprits and successfully prosecuting them. Even if you know what they look like, what their names are, where they live, when they were in the cave, what route they took, the precise nature of the damage done (and can prove that the two events coincide), and have reliable multiple witnesses who are prepared to stand up in court to testify, the case will most likely still not get anywhere, as previous experience has shown. Yes, (some) caves are protected by law but that's as far as it goes, sadly, with the law not been enforced. All rather risible, really. Makes you wonder about a whole bunch of other legislation, too.