When the hooded kid takes the bag out of the dumpster that is supposed to be the missing victim's head, the body-less head blinks on its first reveal.
When JJ is looking at the pictures of past victims she asks " Are those rats?" but her lips stop moving halfway through the question.
The opening shot places the action in Baltimore, Maryland, but shows a bar ("Third and Long") which is a popular sports bar in New York, NY.
The initial crime scene is supposed to be in Baltimore, MD. In the establishing shot the morning after the crime, a palm tree is visible in the background.