Complex sentence: Henry claims to have killed both of his parents, but Sam finds Henry's mother and her dog living in a bare house, confused about Sam's identity (she insists that he is Henry) and refuses to respond to his questions.
Split into simpler sentences: Henry claims to have killed both of his parents, but Sam finds that Henry's mother appears to be alive. Sam visits Henry's mother but finds her living in a bare house, confused about Sam's identity (she insists that he is Henry) and refuses to respond to his questions.