He taught religion for several years and served as headmaster at Saint Thomas Academy, an archdiocesan high school in Mendota Heights, Minnesota.
According to the Diocese of Des Moines, Bullock established a policy addressing sexual abuse in 1988, created the St. Joseph Emergency Family Shelter and St. Mary Family Center, and helped establish the Catholic Pastoral Center in Des Moines.
[5] On April 13, 1993, John Paul II appointed Bullock as the third bishop of the Diocese of Madison; he was installed on June 14, 1993.
[2] He created an office of Hispanic ministry, and he authorized the construction of a social services center to help new immigrants and the poor.
In the final years of his tenure, he created an eight-member sexual abuse review board of mostly lay people to advise the diocese.