Can a law enforcement officer ask you for identification just because he wants to?

There are generally three levels of police-citizen encounters: consensual encounters, investigative detentions and arrest. The Fourth Amendment to the U.S. Constitution protects you from unreasonable searches and seizures -- in your house and on the street. The key word here is unreasonable. If the police do not restrain your freedom of movement in any way, they may approach you to ask you a few questions. So long as a reasonable person in your situation would feel free to walk away, go about their business and disregard the request, the law considers this to be a consensual encounter rather than a seizure and the police are not required to have any suspicion of wrongdoing to initiate the contact. If a law enforcement officer has a reasonable and articulable suspicion that you are engaged in (or are about to engage in) criminal activity, he or she can stop and detain you briefly to investigate. Reasonable suspicion is a standard lower than probable cause. However it must be more than a hunch. This is called an investigative or Terry stop -- named after a landmark 1968 Supreme Court decision in the case of Terry v. Ohio. Such a stop is a seizure, but the law considers it to be one that is justified and reasonable absent probable cause. During the stop, you may be asked questions and to produce identification. You should produce identification when asked. You can refuse to answer other questions. Any stop during which the police restrain your freedom of movement so that a reasonable person in your situation would not feel free to walk away, is considered to be an arrest. This requires the police to have probable cause to believe you have committed, are committing or are about to commit a crime. If you are stopped, I recommend you produce your identification. If you are asked any other questions, ask the officer if you are free to leave. If he or she says yes, go ahead and do so. If you are told no or not until you answer some questions, insist on a lawyer before answering, even if it means a trip to the station house.