We finally have received the full preview treatment we’ve been waiting for. In this trailer for Dexter’s seventh season the main focus is between Dexter & his sister Debra, and for good reason. Now that Debra knows what she knows, will it ever be the same for the Morgan siblings? We also see the Miami PD beginning to put together clues from the latest crime scene which links the killing to a killer from the past….who is that killer? Watch the preview below to find out….