Father Walter entered the Order of Preachers on August 15, 1988. Since his ordination on May 21, 1993, he has served as a college teacher, a retreat master, novice master, and pastor. He is the Religious Assistant to the North American Association of Dominican Monasteries. Most recently, he served as pastor at St. Vincent Ferrer and St. Catherine of Siena Parish in New York City from 2010 to 2021.