Walker was born in upstate New York, had 10 siblings and was drawn to the priesthood after attending traditional Latin Mass with his family in high school. He later joined the seminary, made good grades and enjoyed playing soccer, said the Rev. Joseph Lee, academic dean at the Our Lady of Guadalupe Seminary in Nebraska.
Walker eventually joined a Catholic order that specializes in Latin Mass and became a priest in downtown Phoenix. He recently officiated a younger sibling's wedding in Kansas - the last time he saw many relatives.