In the Army, a fellow Lieutenant had been an informer in the past. He was enlisted, and worked his way into a group that dealt drugs (I never understood this, since we were subject to random drug testing).
When I knew him, he had re-invented himself, having gone to OCS and becoming an officer...he was my XO. He was arrogant, lazy, incompetent, was incapable of interacting with his peers or subordinates...terrible officer.
Mind you I do not condone rape or drug use in our military academies, but having a spy in among honorable men is not the answer.