Courts struggle to define reasonable suspicion and probable cause...
Since police began doing roadblocks, the distinction between "probable cause" and "reasonable suspicion" at a traffic stop has been blurred. These are similar standards, and the courts are still struggling to keep up with new realities about stopping drivers.
Probable Cause vs. Reasonable Suspicion
- Reasonable suspicion is sufficient to justify a stop. Reasonable suspicion means a reasonable observer might suspect a crime. Probable cause is a higher standard wherein the officer believes--not merely suspects--that a crime is being committed. Erratic driving might suggest that a driver is intoxicated. If an officer sees a driver drinking, then the officer has a reasonable belief, or probable cause.
Ingle and Whren
- In People v. Ingle (1975), the California Court of Appeals ruled that stopping a car for mere appearance is a violation of the Fourth Amendment. In Whren v. the United States (1996), the U.S. Supreme Court held that any traffic violation, no matter how minor, was cause for pulling someone over.
Callarman
- In 2001, United States v. Callarman, the 10th Circuit Court supported the police. A policeman conducted surveillance on a head shop. He pulled over a customer and found cocaine. The stop was justified by a cracked windshield that the officer had not noticed until he followed the car. Callarman, the defendant, argued to suppress the search result. The court determined that the stop was legal.
Exceptions to Reasonable Suspicion
- Exceptions to the requirement for reasonable suspicion are border stops and police roadblocks. Roadblocks are constitutional to check for sobriety, to check for undocumented foreigners and to search for dangerous suspects or missing persons.