When the squad car initially pulls up to the seemingly abandoned home, there is a California license plate on the front of the car.
In the opening scene, the Phoenix Police vehicle has a front license plate design that has never been used in Arizona. Beyond that, no vehicles in Arizona, including police vehicles, have front license plates. Arizona stopped requiring front plates in the mid 1990s to save money from having to produce 2 plates per vehicle.
The sergeant stripes worn by some Phoenix police officers are upside-down.
In the second scene with the Chief of Police, he's wearing upside down sergeant's stripes. In the other scenes, he has no stripes.