In Criminal Minds (2005), Emily has bangs. This episode takes place 4 hours after and Emily doesn't have bangs anymore.
During the flashback of the stand-off between Hotch and The Reaper in Hotchner's apartment, the gun held by The Reaper is different from the gun he was holding in the same scene during the previous season finale.
When Agent Hotchner remembers being repeatedly stabbed by the Reaper, the movement of the fake blade is clearly visible due to the slow motion of the killer.