The police stop him. Could be he's lost, in which case the police point him in the right direction. But could be he's looking to score, in which case they escort him to jail. A young woman loitering along the street after dark dressed in a skirt no bigger than a wide belt and a blouse that shows cleavage from here to Harlingen begs the police to check out her story. Years of experience have taught them what kinds of people are generally engaged in prostitution.
Police have a mandate to battle crime.
They use the tools they know work, and profiling is one of them. The Constitution does not prohibit police from considering race as long as they do so for bona fide law enforcement purposes and as long as it is only one of several factors. In a federal lawsuit of the early 1990s, United States v. Weaver, the 8th U.S. Circuit Court of Appeals upheld the constitutionality of an officer's action when he used profiling to apprehend a suspect. The court said that race, when considered in conjunction with other signals, is a legitimate factor in the decision to approach and ultimately detain a suspect. Yet police departments across the nation are researching their traffic stops, noting the race of the people with whom officers come in contact.