The reporting is pretty bad on this one, in one story he's 49 and another he's 59, both by the same author. It's important to remember these are allegations without much detail. He is in jail, pointing this out puts nobody in danger. There's not much info in the story, but an earlier one says he's confessed and been charged.
What's the school's role in this? It seems for years this teacher has possibly been molesting girls within school grounds during school time and it was never noticed? At the very least the need to review procedures, install CCTV, maybe even sack an administrator...
Several years ago an international school in Ubon employed a very well qualified teacher, without any background checks. A Google search would have revealed he'd been jailed in Indonesia for sexually assaulting students.