Law enforcement officers must work under certain constraints. They may not arrest whom they please, search buildings that they please or even pull over whom they please without adhering to certain guidelines. These guidelines are constructed to help ensure that Americans’ civil liberties are respected. As a result, if law enforcement officers violate these guidelines and an individual’s civil liberties in addition, the criminal justice system may be compelled to drop any criminal charges brought against the affected individual.
For example, in order to legally pull over a motorist for suspected drunk driving, the motorist generally needs to have either committed a traffic infraction or have behaved in such a way that officers are given probable cause to believe that the motorist is drunk. Absent a traffic violation or probable cause, law enforcement officers cannot generally pull a motorist over on a suspected drunk driving charge. If they do anyway, the charges against the motorist may need to be thrown out, even if he or she was indeed driving drunk.
Recently, the United States Supreme Court decided that it will hear arguments in a case that questions whether responding to an anonymous tip about reckless driving falls within the guidelines that legally allow law enforcement officers to pull a motorist over. Some jurisdictions only allow officers to pull drivers over based on anonymous tips if an officer has also witnessed reckless driving, while others act on anonymous tips alone.
It is critical that the justice system is run in fair and predictable ways. Hopefully the Supreme Court will settle this question definitively and with the privacy rights of motorists in mind.
Source: Denver Post, “Court: Is anonymous tip enough for traffic stop?” Mark Sherman, Oct. 1, 2013