Castigatory is an adjective that means punitive or intended to punish.
The Latin word castus (cos toose) means ‘pure’ or ‘chaste.’ When we castigate someone, we reprimand them for not being pure or chaste. Any action done for this purpose is considered castigatory.
The board’s castigatory action did little to prevent further problems. It seems James was just determined to be a bad guy no matter how much he was punished.