Dr. Geyer is a hospital administrator as well as a surgeon at Beacon Memorial, Liam's step dad and the husband of his mother. Geyer is a close friend and colleague of Melissa's. Dr. Geyer and Mrs. Dunbar are not aware of Liam's transformation into a werewolf nor his supernatural life in Scott's Pack. In Season 5, Geyer encounters supernatural phenomenon when he treats the sheriff, and removes a piece of bone marrow lodged inside Stilinski, saving his life.
Geyer is an immensely diligent, hard-working and nurturing person, working as a physician, intensely caring towards the sick citizens of Beacon Hills he treats. He is extremely intelligent, having received awards from Harvard. He was also talented being the lacrosse team captain when he was in high school. He is caring, sensitive parent to Liam, being supportive of him, seemingly dedicated to helping his step son overcome his anger problems.