Pagan Babies by Elmore Leonard (2000) Delacorte Press

Father Terry Dunn isn't really a priest.  But no one seems to know that.  He left for missionary work in Africa shortly after the other two guys in an illegal cigarette trafficking scheme blamed him for everything when all he did was drive the truck.  Now, five years later, with his uncle, an actual priest he was visiting has died and he was saying mass in place of the old man, when the Hutu's raided the church and slaughtered the Tutsi congregation, he comes back to America, showing pictures of the starving pagan babies to raise money.