U.S. ATTORNEY Jay Stephens made the right decision yesterday. In announcing that the government would not retry Mayor Marion Barry on the illegal drug and perjury charges that remained undecided after his recent trial, the prosecutor acknowledged that his decision would help lower the temperature in the city and put to rest one aspect of what has been a divisive case. At the same time, he said neither this side effect nor any consideration of the mayor's political future was a determining factor. Instead, the prosecutor said, he simply concluded that a second trial could not add much to what the first had already accomplished.

In spite of the fact that many of the mayor's supporters have tried to portray the jury's verdict as a vindication, it was not. Mr. Barry stands convicted on a drug charge. He was called to account for his actions. The charges against him were investigated. He was compelled to acknowledge drug use, after years of indulging in it, denying the fact and taking endless steps to cover it up. The prosecution has concluded that the expense and ordeal of a second trial would not greatly change this outcome and would not be worth it. That's a hard decision to second-guess.

The initial prosecution accomplished much, and the case is not over yet. Sentencing has been set for Oct. 26, and it would be reasonable to infer from Mr. Stephens's statement yesterday that he intends to ask the judge for a stiff penalty. No second trial is needed to establish the mayor's involvement with drugs. The point has been made.