Alternative time

Stone walls may not, as the poet says, a prison make, nor iron bars a cage; but they will do until something better comes on the market. And in today's market, where new construction of incarcerative facilities cost about $30,000 per cell, the government is always looking for something better.

The perfect sentence, a judge hears, would somehow require of the offender a direct social contribution without putting the offender behind bars. That way we need one less cell, and, most important, we obtain from the malefactor something more valuable than his time and more beneficial than mere punishment.

Pursuing this ideal, prosecutors have taken to urging judges to impose something called ''community service,'' in amounts of time commensurate with the offense.

Unlike Gilbert and Sullivan's Mikado, who fit the punishment to the crime by making the prisoner's anguish equal the victim's, ''community service'' tries to turn the defendant's abilities and skills toward profiting the public as a whole. A trial judge, who has to do the turning, finds the suggestion worth considering.

Sentencing is, under any circumstances, extraordinarily difficult, not least because in most cases the judge knows that imprisonment will benefit neither the victim, society, nor the defendant. Unfortunately, once having raised the possibility, few participants bother anticipating or even contemplating the consequences.

''Your Honor,'' the prosecutor may say, ''I've agreed with defense counsel that if defendant changes his plea, the government will recommend 3 to 5 years in state's prison suspended, with 200 hours community service.''

Both sides then express notable silence on such details as: What ''service''? Performed where? Under whose supervision? Over what time span? When pressed, they will unanimously suggest that ''Whatever the Probation Department requires is all right with us.''

All right with the lawyers, perhaps, but not with the judge. Though he respects and relies upon the insight and wisdom of the probation officer, the responsibility of sentencing is his alone. As a judge soon learns, one of the problems with ''community service'' is that people - not least, defendants - forget that service is indeed part of the sentence. We would do better to call the process ''alternative sentencing,'' or, more accurately, ''alternative punishment.''

To most of us, ''community service'' evokes images of hospital candy-stripers , Boy Scout paper drives, and volunteer civic improvement: something we do only after attending to our important personal concerns. A defendant may well feel that his service is, if not his most insignificant commitment, certainly well behind job, family togetherness, vacations, and general recreation.

If the public, the judiciary, the prosecution, and the defendants are not to regard the idea as a correctional boondoggle, everyone must understand that out-of-jail employment is truly an alternative to clanging-door incarceration.

Thus, before approving an arrangement, a judge must know the organization which will be employing the defendant. He needs the name of defendant's supervisor, the exact tasks he will be performing, and the weekly work schedule. Moreover, the set number of hours - whatever the amount - should be performed as quickly as possible.

Letting things dribble out in 2- or 3-hour-a-week chunks merely trivializes the process and gives the defendant (and his victim) the idea that he has gotten away with something.

Finally, to ensure that everyone understands how seriously the court regards the sentence, the judge requires weekly reports from the work supervisor. Any indication that the defendant is losing interest results in a warning that he risks a revision of his sentence.

In short, the defendant has to realize that however irksome and unpleasant his temporary employment, he must give it first priority. Of course, it is burdensome and frustrating to give up a family outing or a planned vacation just to perform unpaid labor in a hospital. The trade-off is not really unfair, though: commitment to the job rather than commitment to prison.