A proposal to bring Bay State's criminal code, circa 1865, up to date

Justice in Massachusetts is anything but even-handed. Two people convicted of identical crimes, with similar backgrounds, and under the same circumstances often face very different sentences.

The leniency or severity of a sentence often depends on the individual trial judge, whose decision may be shaded by his or her philosophy on corrections.

Conservative members of the bench usually give stricter sentences than their liberal colleagues, some of whom question the merit of longer jail terms or stiffer fines.

What the Bay State needs is a set of guidelines to help judges determine the punishment that is most appropriate for the convict - and for the protection of society as a whole.

But guidelines should retain a certain measure of flexibility, so a judge's hands are not tied in the meting out of justice. The judge should be free to consider special circumstances of the crime, or the offender's background, when deciding whether to order a shorter or longer prison term than what is prescribed by law.

These goals could be achieved in the commonwealth under a setup known as ''presumptive sentencing.'' The reform, which appears to be working well in several other states, will be pushed hard this year on Beacon Hill as part of a proposed recodifying of Massachusetts criminal laws.

Presumptive sentencing is so named because, under such a setup, it is presumed that all criminals convicted of equally serious crimes will serve similar periods of incarceration.

Under presumptive sentencing, all felonies would be grouped into one of several classifications, based on severity of the crime. For each level of crime , a sentence range would be prescribed (say, three to five years) along with a fixed maximum (but no more than 12 years).

For example, the presumptive sentence for kidnapping in the first degree might be 10 to 15 years' imprisonment. Ordinarily, the trial judge would impose a prison term within those bounds. However, a judge could consider special circumstances of the crime or of the felon's record, and then impose a lighter or stiffer sentence. At the time the judge would be required to state, in writing, the reasons for skirting the guidelines.

In some instances, the proposed sentencing range is lower than current maximums. But it should be noted that few convicted felons are given the longest imprisonment allowed. Of those who are, most do not spend their entire sentences behind bars because of parole and other early-release bonuses, such as time off for good behavior.

The concept of presumptive sentencing is winning more and more supporters within lawmaking circles. But the advocates differ slightly over what should be included in a revamp of the sentencing structure - the inclusion of parole, for instance.

Whether there will be enough votes to enact such a measure in the coming months is uncertain. Many senators and representatives tend to shy away from complex matters at a time when they are preoccupied with reelection campaigns.

Last year, a measure embracing presumptive sentencing was filed, but it made little headway. If passed, it would have been the first major recodification of ''crimes against person'' since 1865.

Its chief sponsor, state Rep. W. Paul White (D) of Boston, co-chairman of the Legislative Commission on Uniform Sentencing, has submitted a similar proposal this year.

In addition, Gov. Michael S. Dukakis is expected within the next few weeks to file legislation that may be even more far reaching. His proposal is likely to be based on the recommendations of his anticrime council, a panel that includes representatives of various state agencies, Attorney General Francis X. Bellotti, several district attorneys, chiefs of police, lawyers, judges, and others. The panel has given particular attention to the problem of sentencing inequity and its impact on the administration of justice.

Governor Dukakis is a longtime critic of mandatory sentencing, an approach that has had considerable appeal within Bay State legislative ranks. In his Jan. 17 State of the State message, the governor made it clear that provision for presumptive sentencing will be one of his main priorities this year.

Dukakis stopped short of saying what he intends to recommend, but he called for ''a criminal justice system which is a firm, sure, and effective deterrent to crime. That means new sentencing legislation in 1984 that is both tough and fair,'' he added.

Attorney General Bellotti, who also is committed to presumptive sentencing, says such legislation should involve ''crimes against person'' as well as ''crimes against property'' (such as burglary, arson, and larceny).

Bellotti also maintains that mandatory sentencing is not the best direction. The legislation now being shaped presumably would leave in place stringent minimum imprisonment terms covering drug pushers, those who attack elderly persons, and repeat car thieves.

Mr. White's legislation, which embraces presumptive rather than mandatory sentencing, includes only those crimes in which an individual is the direct victim, such as second-degree murder, manslaughter, kidnap, rape, assault and battery, and armed robbery.

All such felonies would be grouped into six classes with a different range of imprisonment provided for each class. For instance, rape in the first degree would carry a presumptive sentence of 10 to 16 years, with a maximum of 22 years. The least serious ''crimes against person'' would be punishable by incarceration for five to 10 months, but up to three years would be permissible if the trial judge felt the circumstances warranted a stiffer penalty.

The thrust of this, or any other sentence restructuring worthy of serious legislative consideration, should be to rehabilitate lawbreakers and get tough with habitual offenders. These latter, often called ''career criminals,'' pose the greatest threat to public safety. Thus, their incarceration for longer periods would seem particularly desirable.

Shorter but specific sentences for some other criminals, especially those convicted of their first felony, would also seem to make sense. This practice also could help save the commonwealth millions of dollars by avoiding the need to build more prisons and to care for an already fast-growing inmate population.