U.S. ATTORNEY Charles F. C. Ruff's decision to make greater use of preventive detention was necessary. Preventive detention is the one weapon in the local prosecutor's hand that lets him address the danger of allowing certain suspects to return to public life who have been charged with a violent crime but who have not yet been tried. Because a request for preventive detention requires the prosecutor to reveal much of his case, and to bring the case to court in 60 days, the U.S. Attorney's Office has limited its use of the law to only the most alarming cases. Mr. Ruff now plans to use the law in more common cases.

Under the present bail laws, a judge cannot legally consider the danger involved in releasing a defendant unless the prosecutor invokes the preventive detention statute. The judge can only consider how likely the person is to return to court for trial. But more and more citizens want the judge to add to his deliberations the danger a defendant may pose on the street. The public is fed up with seeing a defendant with a history of violent crime caught, only to be released.

The preventive detention law, quite correctly, does not let judges lock up all persons with such a history. Before they can be held in jail pending trial, prosecutors must also show that the case against them is strong. This requirement is designed to reduce incidents in which a suspect jailed before trial is later acquitted or has the charges against them dropped.

This law strikes a delicate balance between the need to protect the public against dangerous suspects and the presumption that every suspect is innocent until proven guilty. The history of its use in the District demonstrates that careful administration can protect innocent persons from the abuses that led to reform of the bail laws a decade ago. Mr. Ruff's decision to invoke it more frequently does not indicate a return to the old era. It should be interpreted as an effort to improve the screening process that distinguishes between suspects who have forfeited their right to freedom and those who have not.