Are there Bad teachers? Is Mara in the Sanga?

I have had an experience with a top teacher, Regional Assistant Teacher, and Center Manager acting in ways very disturbing to the path. Later I saw clearly that they were controlled by Mara or had energy in the Mara realm, may be interested in making very difficult Sankhara. How can a serious student navigate these dangers to reach liberation? If the Sangha has lies, killing beings, Traps students and Practitioner s in a the type of life a student of Buddha seeks to be free from? Are these dangers in monks? Can we admit and face what influence we have acting upon us or act out ourselves or will this lead to more ego I am, I am not... Etc. More confusion and controversy.