Supernatural - Houses of the Holy Season 2 Episode 13

The Winchester brothers look into the murders of several people who say they were visited by an angel and were simply carrying out God's will. After further investigation, Sam and Dean find that those murdered were guilty of secret crimes, but the brothers split on what they think the truth is -- Sam believes that there is an angel that caused the murdered, but Dean thinks that a demon is the cause of the deaths. However, Dean soon changes his belief when he sees the unexplainable.