In September, District voters will be asked to approve an initiative providing mandatory minimum sentences of five years in prison for anyone convicted for the first time of committing a crime of violence with a firearm and from one to four years for a variety of drug offenses. This proposal raises a number of serious questions.

Mandatory minimum sentences for weapons and drug offenses are not a new idea. Studies of the experiences in Massachusetts, Michigan and New York, among other states, have concluded that such sentences have little or no long-term effect on the amount of either crime or punishment and may have serious adverse effects on the working of the criminal justice system.

The District is in the upper quarter of the nation's jurisdictions in the length of prison sentences imposed and ranks first in the number of persons incarcerated in relation to its population. Despite a high-quality, efficiently run trial court and a first-rate prosecutor's office, the District struggles with an ever-increasing caseload, an ever-increasing delay in the disposition of those cases and an ever-increasing prison population, while the resources available to the courts and prisons remain severely limited--barely able to maintain current levels of operation.

What will happen, then, if mandatory minimum sentences are superimposed on this system?

First-time armed offenders, to whom the new penalty would apply, are already subject to life imprisonment, and it is unlikely that there would be any marked increase in the minimum terms imposed for such crimes as murder, rape, robbery or assault with intent to kill "while armed." The effect of the proposed new law would be to transfer discretion from the court to the prosecutor, who alone would have the power to invoke the mandatory minimum, whether in order to improve the government's plea bargaining position or to bind the judge's hands at the time of sentencing.

Drug offenses would present different problems. The initiative would require that any defendant convicted of possessing with intent to sell or selling such drugs as cocaine or Preludin (the most common pill sold on the street) serve a minimum prison term of 20 months and a minimum of four years for heroin and other narcotics. This sentence would be imposed whether the defendant was a first or second offender, was a major distributor or a street-corner salesman, or was arrested with 10 bags (the street sales unit) of 3 percent pure heroin or 10 ounces of 90 percent pure heroin.

Some 85 percent of all criminal cases are disposed of by pleas of guilty. If this were not so, the judicial system would grind to a halt. But a defendant will enter a guilty plea only if he hopes for some leniency from the sentencing judge. In the hundreds of felony drug cases prosecuted each year in Superior Court, if each defendant knew that he would have to serve a minimum of two or four years in prison whether he was convicted by a jury or pleaded guilty, there is little doubt what he would do. The result would be chaos.

Reform of the criminal code and its sentencing provisions has been studied by the Law Revision Commission and the Judiciary Committee of the D.C. Council, and recent legislation attempts to balance enforcement with a concern for the rights of the individual, a balance that is not reflected in this initiative.

One aspect of the initiative deserves special scrutiny. Because D.C. law says a judge must sentence a convicted defendant to a maximum not greater than that provided by law (15 years for selling heroin; five years for selling cocaine and other non-narcotic drugs) and a minimum not more than one-third of the maximum actually imposed, the initiative would require the judge to sentence every heroin defendant to almost the maximum--four to 12 years, and all other defendants (with the exception of marijuana sellers) to the maximum--20 months to five years, no matter what the extent of their involvement. So this is not merely a mandatory minimum proposal; it is an irrational abolition of sentencing discretion.

Existing mandatory minimum sentences for murder in the first degree and for second armed offenders serve an important law enforcement purpose. But to limit a judge's choice so drastically in the case of first offenders and across such a wide range of drug offenses incurs too great a risk of injustice. Some revision in current sentencing practices may be needed. Too much discretion may now be vested in both prosecutors and judges. Maybe we should adopt a sentencing scheme with a narrower range of penalties and statutory guidelines for the court; or establish fixed terms of imprisonment for all offenses and abolish parole; or create a mandatory minimum sentence for a second drug offense. But the proposed initiative risks consequences that its proponents have not adequately considered and for which one doubts they would want to be held responsible.