the vehicle without violating the Fourth Amendment's proscription of unreasonable searches and seizures. Drivers and passengers may be frisked for weapons upon reasonable suspicion they are armed and dangerous. If police reasonably suspect the driver or any of the occupants may be dangerous and that the vehicle may contain a weapon to which an occupant may gain access, police may perform a protective search of the passenger compartment. Otherwise, lacking a warrant or the driver's consent, police may not search the vehicle, but under the plain view doctrine may seize and use as evidence weapons or contraband that are visible from outside the vehicle. As decided in Ohio v. Robinette (1996), once an officer returns the driver's identification, there is no requirement that the officer inform the driver they are free to go; therefore, although the encounter has been turned into a consensual encounter, questioning can continue, including a request to search the vehicle. Pretextual stops Pretextual stops are a subset of traffic stops deemed constitutional by the Supreme Court in Whren v. United States (1996). They occur when a police officer wishes to investigate a motorist on other suspicions, generally related to drug possession, and uses a minor traffic infringement as a pretext to stop the driver. In the case of Whren, the defense used a "would have" rule: asking if a reasonable police officer would have made the stop without the suspicion of other criminal behavior. Some consider that pretextual stops can allow for racial profiling to occur. There are numerous petty violations a driver may make and the officer can be selective about whom to pull over to investigate. Sixteen states ban pretextual stops based solely upon racial profiling or other factors: Racial disparities Police officers may develop schemas after continuously being exposed to certain environments, like high crime minority neighborhoods, which can lead to their association of crime with race instead of suspicious behavior. Officers who have been in the police force for longer are more likely to have suspicions based on non-behavioral reasons. Even forms of American culture that perpetuate negative stereotypes such as blacks being violent can cause those who consume them to associate black people with these stereotypes, even if they do not believe them, making implicit bias a possible factor in arrests. Black and Hispanic people are more likely to be targeted, and are more likely to be stopped than their population