A TASK FORCE of federal and local officials is now at work on the logical next step in the evolution of self-government in the District. It is the transfer of the power to prosecute criminal cases from the Department of Justice to either the corporation counsel's office or a new District prosecuting attorney.

This transfer should have occurred some years back when the local court system began to gain its independence from federal control. It does not make sense to have the federal government, through the U.S. Attorney, handling the prosecution of almost all local crimes in what is now the equivalent of a state court system.

But the transfer was postponed, or rejected as unfeasible, for many reasons, including fear that it would make crime control in this city even more difficult than it already was. That fear persists and may be the major stumbling block even now. It arises because this is one area of local government in which federal domination has been a blessing. Because the prosecution of crime has been handled by an arm of the Department of Justice, the caliber of the lawyers handling the cases has been remarkably high. Few cities have been able to attract a corps of prosecutors as competent and successful as that provided by the U.S. Attorney's office for many years.

Thus the District's problem in taking over this aspect of self-government is to devise a system that ensures that the level of competence (and the conviction rate) of its prosecutors does not decline. This can be done, but it won't be easy. It requires, above all, a convincing demonstration by the District government that it is committed to excellence and that second-class legal work, long a mark of the corporation counsel's office, will not be acceptable.

There are other problems. Should the prosecuting functions go into the corporation counsel's office, where the appointment of Judith Rogers is clearly a step toward improving it-or into a new office? If the latter, should the prosecutor be elected or appointed? Should the entire range of the U.S. Attorney's jurisdiction, which runs from petty larceny to murder, be transferred at once or in phases as was the transfer of judicial power some years ago? How should the transfer of related functions-especially the handling of prisoners and the assignments of the U.S. marshal's office-be handled? How should it all be financed? The task force now at work will, no doubt, provide recommendations on all these matters.

The inevitable question, however, is: Why change a system that works so well if there are so many problems in changing it? The answer is that, until the District gains control over the prosecution of its own crimes, self-government in the District will be incomplete.