Kolender v. Lawson

A state criminal statute that requires persons to identify themselves and to account for their presence when requested by a police officer under circumstances that would justify a valid stop is unconstitutionally vague. This statute encourages arbitrary enforcement by failing to clarify what is contemplated by the requirement that a suspect provide a “credible and reliable identification.” The statute vests virtually complete discretion in the hands of the government to determine whether the suspect has satisfied the statute and must be permitted to go on his way in the absence of probable cause to arrest. Therefore, the statute is void-for-vagueness. The void-forvagueness doctrine requires that a penal statute define the criminal offense with sufficient definiteness that ordinary people can understand what conduct is prohibited and in a manner that does not encourage arbitrary and discriminatory enforcement.