ERIC JAMES LONG, charged with sexual offenses against six young boys in his Silver Spring neighborhood and previously convicted twice on similar charges, was employed by a Montgomery County private school. Legislation is now pending in Annapolis that would require criminal checks of persons seeking employment in schools or day care centers. But even in the absence of this law, the system failed to protect the children who regularly came into contact with Mr. Long because probation authorities never notified the school where he worked of his conviction.

State probation officials confirm department policy to forbid this kind of employment for child abusers on probation but say that in this case any one of a number of things could have gone wrong. The pre-sentence report given to the judge at the time of the second conviction could have failed to note the earlier conviction. Or if plea bargaining was involved, there might not have been a pre-sentence report at all. The court could have ordered unsupervised probation -- a bad mistake with this kind of offender -- or the probation officer assigned to Mr. Long could have goofed by failing to get in touch with his employer. No matter what the explanation, there is no excuse. Probation didn't work in this case, and some children were hurt, if the charges are true.

Problems with probation are not unique to this area. A Rand Corporation study, funded by the National Institute of Justice and released last week, provides startling evidence of the inadequacy of this form of corrections in California. The data have significance in most other states as well. The Rand researchers tell us that between 60 and 80 percent of all convicted criminals are placed on probation in part because of a shortage of adequate prison facilities.

Probation was originally conceived as a less expensive and more humane way of dealing with non- dangerous offenders by keeping them in the community with supervision and with a plan for rehabilitation. But in the California sample studied, one- third of all adults released on probation had been convicted of felonies. Within the 40-month period of the study, 65 percent of these felony probationers were rearrested, the overwhelming majority charged with serious, violent crimes. The study concludes that these felons pose a serious threat to the public safety for whom traditional forms of probation were entirely wrong. What should be done?