IT WAS not surprising that Federal Judge Edward M. Curran held unconstitutional the Metropolitan Police Department's policy authorizing officers to stop pedestrians anywhere, anytime, and ask them to show identification and account for their presence. This sweeping policy is so clearly an invasion of personal privacy that it should never have survived for the eight years that have passed since it was set out as a general order of the department. Rather than mourn its passing, the District government should quickly issue a new order setting out the conditions under which officers can legally make such requests: whether they have reason to believe the pedestrian has been involved in, or is about to be involved in, a crime.

These contacts between officers and pedestrians have been, no doubt, a useful police tool. A person who has just given an officer his name and address is less likely to commit a crime in that immediate neighborhood. The contacts helped solve crimes occasionally, too, because the information was filed on index cards that could be reviewed when a crime was later reported in that area.

Nevertheless, the right of any citizen to walk down any public street without having to tell the police what he is doing there outweights these benefits. The police department's lawyers acknowledged that when they conceded before Judge Curran that pedestrians were free to ignore the officers' questions and walk away. But how many pedestrians would be willing to try to exercise that freedom? The difference between an officer's request for information -- that's how the lawyers described these contacts -- and a demand is not always easy to determine. Any police officer's words carry with them a measure of official authority, regardless of how carefully and courteously they are spoken.

Nothing in Judge Curran's order, of course, prohibits the police from seeking identification from anyone they have reason to believe has committed a crime. That reason doesn't have to be sufficient to make an arrest or even to detain a person for questioning. But it ought to be more than an officer's sudden impulse to find out who someone is or why he or she is in a particular neighborhood. The right of citizens to be left alone and to wander anonymously in public places is too much a part of individual freedom to permit any government agent to interfere with it without some clear reason.