Complex sentence: Hicks tells him that his brother Owen was mortally wounded and his sister-in-law and ex-girlfriend Shannon were killed by vampires and Priest's niece, Lucy, was kidnapped.
Split into simpler sentences: Hicks tells him that his brother Owen was mortally wounded by a vamp-attack. His sister-in-law and ex-girlfriend Shannon was killed, and Priest's niece, Lucy, was kidnapped.