On Feb. 23 the Supreme Court refused to review two tough cases, one from New Jersey, the other from New York. Both cases challenged the validity of laws, known as "Megan's Laws," that provide for the indefinite surveillance of convicted sex offenders.

By refusing to hear these particular cases, the court leaves the laws on the books. This does not mean that the court thereby has approved them. Other challenges are in the works.Forty-seven states have enacted a "Megan's Law." The acts take their name from 7-year-old Megan Kanka, who was raped and murdered in the summer of 1994. Her assailant was a repeat sex offender, Jesse Timmendequas, who lived across the street from her home in New Jersey.

Stunned by the horror of the crime, the New Jersey Legislature wasted no time. In October of 1994 the state adopted a law that provides for informing a community that a serious sex offender is nearby. Megan's Laws work in roughly this fashion:

When an offender is about to be released from prison, local prosecutors conduct a hearing. One prosecutor comes from the original venue, another from the locality in which the offender will reside. Their purpose is to assess the dangerousness of the felon according to a three-tiered classification.

About two-thirds of the offenders - those who are thought to be the least dangerous - wind up in Tier I. At this level prosecutors notify only local law enforcement officers of a prisoner's release. Another 30 percent are placed in Tier II, which projects a higher degree of danger. Alerted to Tier II offenders, police notify nearby schools, day care centers, summer camps and the like. Tier III covers released prisoners who are thought to be the most dangerous of all. This classification adds house-to-house notification to the law's requirements under Tier II.

I hate to be ambivalent, for ambivalence waters down the juice of pure opinion, but in the matter of Megan's Laws I'm ambivalent. I cannot vote an uncompromising yea or nay.

There's another perspective. Perhaps I have been immersed too long in the pickling brine of constitutional law, but some aspects of a Megan's Law leave me sorely troubled.

For one thing, there is the problem of offenders who were convicted and sentenced before a Megan's Law became operative. New Jersey's three-tiered system is plainly a form of additional punishment. Only a sophist could argue otherwise. The state especially stigmatizes offenders in Tiers II and III, and effectively stigmatizes them for life.

I am troubled by the whole business of predicting behavior. There is no prophet's license in New Jersey. Psychiatric testimony in support of a Tier II or Tier III offender may be informed conjecture, but it cannot ever be much more than that.

In theory, a convicted sex offender who has completed his prison sentence has paid his debt to society. This is not a bad theory. The Eighth Amendment says a state may not impose punishments that are cruel and unusual. I'll buy that. Does a Megan stigma meet the Eighth Amendment test? Is a Megan offender deprived of his liberty without due process of law?

I submit the questions, and I regret that the high court, for its own unexplained reasons, last month declined to answer them.