Who is Justin O'Carroll from Cradle and All and what is their importance?

Justin is a Catholic priest. He is hired by the Vatican to investigate a strange set of events. Although he is faithful to his vows of celibacy, he has always been secretly in love with Anne Fitzgerald. Anne had refused him previously, despite her own feelings, causing Justin to continue with his priesthood. As such, he moved up through the church's hierarchy and became a trusted advisor.