At my school, the pre-med committee was 12 people, it consisted of roughly equal representation from Science (2 Bio professors, 1 physics, 1 chemistry), Arts , and Business. They got your grades each year, if you GPA dropped below a certain threshold by the end of junior year, you were dropped from consideration. During senior year, you submitted LOR's and a personal statement. Then you had an interview with the committee. They basically set up in a board room and had you sit at the head of the table and then each committee member asked you questions. After the interview, they each gave rating, then a committee letter was drafted by the head of the committee.