Sorry, but this should surprise no-one.  Not that a CO was bringing it in, nor the fact that a fellow CO was so blase and willing to assist [until he picked up on a serious bust going on that he had just put himself on the wrong side of].  Drugs inside DOC facilities [and many other jails and prisons] are not at all uncommon - just very expensive.  The mj may actually be a good idea, but the heroin prevents someone from an opportunity to get clean in seclusion from temptations.