The question of whether the four uniformed Baltimore policemen involved in the incident that left Officer William H. Torbit Jr. dead needed more cues that their target was a fellow officer is not the only one raised by the shootings early Sunday morning outside the Select Lounge, and maybe not even the most important one. But it is the one thing the police can most easily do something about, and they're right to immediately require plainclothes officers to put their uniforms on pending a further review of department policy.

We don't know why Officer Torbit pulled his weapon in the first place, or why he, as police believe, fired six to eight shots at Sean Gamble, an unarmed, 22-year-old man. We do not know what role Mr. Gamble played in the melee that preceded the shooting. And we don't know what prompted the other four officers to begin firing into a crowd and to keep firing, an average of more than eight shots each. We may not get answers to all those questions for quite some time; the four officers have not yet provided statements to the police, so investigators are left to piece together the story from surveillance tapes and witness statements, a difficult task given the chaotic scene.

But we do know that Officer Torbit, who normally patrolled the drug-infested areas around Pennsylvania Avenue, responded to a distress call by another officer at the Select Lounge, dressed, as he normally was, in street clothes — witnesses say a dark jacket. The only thing that identified him as a police officer was a badge around his neck on a chain, but it got dislodged at some point — whether before or after the shooting is unclear. It is also unknown whether Officer Torbit told dispatchers that he was headed to the scene in plain clothes or whether the information was relayed to other officers.

Whatever the case, being out of uniform, without even a police jacket, did Officer Torbit no favors. It certainly wouldn't have helped him to calm the scene outside the club, and it definitely made it harder for his fellow officers to identify him. There's no way to know whether the policy Police Commissioner Frederick H. Bealefeld III imposed Wednesday requiring all plainclothes officers to don uniforms while the department re-evaluates its procedures would have prevented Sunday's clash from turning deadly. But it certainly wouldn't have hurt.

What about other circumstances? The reason police give for having some of their officers wear civilian clothes is that it helps them get close enough to illegal activity, such as drug dealing, to observe it in progress. The officers not only wear plain clothes but they also drive in unmarked cars, often rentals so that criminals don't know what kind of car to watch out for.

That makes sense, but other departments have found a way to strike a balance between making officers unrecognizable to criminals and recognizable to their partners. New York, for example, has plainclothes officers wear a distinctive color each day.

That might help, but Baltimore should consider making the requirement of full uniforms for all of its officers permanent. If the department's goal is to be able to patrol the streets stealthily, the rotation of unmarked cars is probably the most important thing. When the officers jump out of their rentals with badges hanging around their necks, the criminals probably figure out things just as quickly as if they were in uniform.

And there's more to be gained from wearing a uniform than just being recognizable to fellow officers. Uniforms denote a degree of professionalism and command respect in a way that jeans and T-shirts don't. Some officers may feel more comfortable patrolling the streets in civilian clothes, but uniforms are safer, and they project a better image in the community.