Only after a king-size political waffle did Marion Barry finally acknowledge earlier this year that maybe the offer of big federal help in building some kind of prison facility in the District of Columbia was important enough to accept and support. But he then resorted to an old executive dodge: the naming of a citizen study commission, allegedly to study and recommend a site. At the time, Mayor Barry commented that he'd had trouble finding seven people to serve, that people were telling him they didn't want "to be in front on this one," that they were saying, "Mayor, you take this one yourself." We thought that was a fine idea: Mr. Barry is, after all, the mayor. But no. A commission was formed, and it has come up with an answer -- but to the wrong question.

That commission has rejected a resolution to build a new prison, calling instead for alternatives to incarceration. But the question wasn't whether to build a facility, but what to build and where. Back to you, Mr. Barry: how many more inmates at the jam- packed D.C. Jail or at Lorton can the city release under "alternatives"? How many more convicted criminals can be released in the custody of others, assigned to halfway houses or given probation? It took a judge's order to get the mayor to make this logical head count -- and he now says the population at the D.C. Jail can be reduced by 1,000 in 90 days.

Certainly there are constructive alternatives to incarceration. But they are only part of a delicate balance that has to include secure facilities for those adjudged to be too dangerous or otherwise unready to rejoin society. District residents are entitled to that protection.

Some commission members from Wards 7 and 8 are genuinely concerned that their wards are most likely to wind up with a new prison and all the feedback that may generate among their neighbors. That is a proper matter to be considered in the site selection. No ward in the city should be arbitrarily or politically excluded from consideration in reaching a decision. But a decision should be reached now, and Mayor Barry should see to it in the fairest and most expeditious way possible.