This case was about the rules that govern searches and seizures of property from cars that have been stopped by the police. In this case, the Supreme Court clarified rules about searches and seizures and broadened the power of the police to search the contents of cars without first getting a warrant.
In this case, a man named Albert Ross had been pulled over by the police, who believed that he had heroin in the car with him. They then searched the car. Finding a closed paper bag and a leather zippered bag, they searched those as well, finding heroin. Ross was arrested. He claimed that the police had violated the 4th Amendment by searching his private property without a warrant. The Court had previously ruled that a very similar search was illegal in Robbins v. California. In this case, however, the Court reversed itself.
In this case, the Court held that the search was legal. It then clarified the rules on searches of cars stopped by the police. It ruled that, when the police legally stop a car and are searching for a given item, anything in the car that could hold that item may legally be searched. Since the bags could have held heroin, they were fair game to be searched even without a warrant.