ScienceGrad

Greetings fellow grads. I was reccently made aware of a serious instance of violating academic integrity of a Biology class I TA'd for last semester. One graduate student (we'll call him Mr. Smith) for his recitation did the following: 1) Developed a systematic method of allowing the students in his session to raise their hand during the exam, he would quickly go over to them, and he would non-verbally aid them in telling whether an answer was correct or not and 2) Would attempt to memorize the questions from the exam when the supervising professor let the TAs proof-read the exam for mistakes and then go an review as much of the exact material that would be on the exam as he could remember during recitation. This was apparently reported by another graduate studnet who noticed the during-test assistance (we were in two separate testing rooms and I was in another so I never saw it myself), and heard through students in other recitations that this particular recitation got a number of exact exam questions and went over them prior to the exam. The report was made to the professor in charge of this class after two midterm exams where this activity had contonued, however the professor in charge of the class was the PI of Mr. Smith... During the final I recall the supervising professor being extremely strict and watching all of us like a hawk such that we were told not to say anything to any students when they had a question, however I didn't think anything else of it at the time. All of these students who were cheating all got A's or close to it in the class. I remember I was assigned to imput grades after the second midterm and Mr. Smith's students' average was on another planet compared to everyone else's recitations, so in hindsight combined with what I know now there was some serious cheating going on. My questions is this: do I still have a responsibility to report this to the department chair? It seems the supervising professor was told of the problem and covered it up to prevent himself from looking bad (he will be up for tenure soon), and protect his graduate student. Furthermore, all of these students got away with blatant cheating on two out of three exams. Shouldn't they recieve an F in the class? Or is it just too late for anything to be done anyway (this was F13 semester)? EDIT: I realize it is entirely possible the department chair was already made aware of the situation by the supervising professor and he decided this was the right course of action, but I am assuming for this scenario that is not the case.