Continuity mistake: While George Foyet is stabbing Agent Hotchner, the knife is extending from the handle. The blood is at the top of the blade, and as he removes it, the blood moves to the bottom of the blade, while the top remains clean.
Continuity mistake: In the scene where the unsub is having a tea party with her "dolls", look at the diabetic woman's right hand when the unsub is pouring her tea. When the tea is being poured the doll's right hand is palm up. When the camera cuts to a close up of the cup the doll's hand is face down. The doll is paralyzed due to the drugs and had not regained control of her body yet, making it impossible for her to move the hand on her own.
Continuity mistake: At the end a shot is shown of the FBI airplane in mid air. The airplane shown is a Gulf Stream V; which has a very distinctive nose. After the scene inside the airplane; another shot is shown of the plane's exterior, however all of a sudden they fly a Gulf Stream 100, which is a significantly larger plane and a very different design. (00:41:05 - 00:45:00)
Chosen answer: Black SUVs are common police, military and dignitary vehicles around the world. It is not too much to assume they could be rented or owned by the police forces in the areas.
kristenlouise3
Other people have explained it but fore more information, federal cars would most likely be brought to the airport from the nearest agency, so they can drive out to their locations especially in rural situations.