Legal requirements and procedures for vehicle stops

¶ … stop legal?

The stop was indeed legal. According to the ruling in Delaware v. Prouse, 440 U.S. 648 (1979), the police may not randomly stop a single automobile to simply check license and registration - they must actually and reasonably believe that the stopped car violated some traffic law.

In this case, the cops did not believe that a traffic law was violated, but did believe that the stopped people were loitering. This is probably close enough to the violated traffic law rule, so the from that angle, the stop was legal.

Another way the detectives can demonstrate that their stop was legal is to show that they had set up some version of a checkpoint, whereby they were checking some percentage - randomly - of cars that they encountered. Since stopping a car is a seizure for purposes of the Fourth Amendment, police generally must have at least reasonable suspicion to justify the stop. However, the Supreme Court in several cases including Michigan Department of State Police v. Sitz, 496 U.S. 444 (1990), has ruled that checkpoints can be valid without reasonable suspicion if cars are stopped according to some neutral articulable standard - for example, every car or every third car - and the government interest in conducting the checkpoint outweighs the degree of the intrusion in fact.

In this case, even without a checkpoint, the stop may have been legal because the detectives had reasonable suspicion. As they noted, people don't hang out in that area and they knew a robbery had been committed.

Specifically, police officers may order vehicle occupants out of a car. Provided that a police officer has lawfully detained a vehicle for a traffic violation, the officer may order the occupants of the vehicle (that is, the driver and the passengers) to get out. The rationale here is that since the occupants have already been detained, the added intrusion of forcing them to exit the car is minimal, while the potential danger to the police officer in allowing the occupants to remain in the car is great.

Also, pretextual stops are acceptable as well. If a police officer has probable cause to believe that a traffic law has been violated, the officer may stop the suspect's car, and this is true even if the officer's ulterior motive is to investigate whether some different law - for which he lacks the reasonable suspicion standard - has been violated or is being violated. This rule stems from Whren v. U.S., 517 U.S. 806 (1996), in which police in a high drug area sopped a defendant's car after observing him wait a long time at an intersection, abruptly turn without signaling and speed of at an unreasonable speed. While the vehicle is stopped for this pretextual purpose, the cops may search the car even after the business of the traffic violation is taken care of.

In this case, there was no traffic violation per se, but there was a potential crime - i.e., loitering, so the pretextual rules would still apply.

Once the car is stopped for reasonable suspicion, road block or pretextual purposes, the police officers may search any part of the car where they reasonably believe contraband may be hidden.

For instance, if they are searching for a body, they may not search in the glove compartment, but if they are searching for weapons, they may. In this case, with the robbery having been committed, they could have reasonably been searching for weapons, so it was perfectly legal to look in the back seat and see - in plain view - the weapons and take them for evidence.