He is citizen of the Northern Cheyenne Nation of southeastern Montana. Killsback earned a Doctorate of Philosophy degree in American Indian Studies with emphases on tribal government, tribal law, federal Indian law, and American Indian culture and spirituality. Killsback grew up on the Northern Cheyenne Indian Reservation and he culturally and spiritually identifies himself as a Cheyenne person. He has published articles related to tribal customary law, historical theory, and American Indian history, culture and philosophy. Killsback teaches graduate and undergraduate courses like American Indian Leadership, American Indian Research Methods, and American Indian Customary Law and Governance.