IT WAS A GOOD and unusual thing the other day when the Maryland Court of Appeals told the state's judges to treat the juveniles who appear before them with an "even hand."

The situation the Court of Appeals faced cried out for such an admonition. Three youths had broken into a home in Silver Spring in 1977 and torn it apart. After they were caught, two were released when their parents agreed to pay their share of the damages. The third, whose mother couldn't afford to pay his $400 share, was sent to court to face other sanctions, including a possible term in jail.

You don't have to know any more about the case than that to know this solution was unfair. Judge Douglas H. Moore Jr. thought so when the matter was presented to him and he dismissed the charge against the third youth. But the Court of Special Appeals didn't see it that way because the third youth had some "emotional problems" that justified judicial action in his case.

No way, Maryland's highest court said last Thursday; although officials dealing with juveniles have "wide discretion" in determining how to handle each individual youth, it said, they must deal with them evenhandedly.

What is most striking about this decision is that local officials think it will influence their handling of several juvenile cases each month. What has been going on here? A juvenile court judge concedes that, as a rule, "Wealthier youths may have been able to buy their way out of trouble."

The first principle of juvenile courts ought to be that the financial status of a youth's parents is irrelevant to how a case is handled.The ability of parents to make restitution for damages a child has inflicted is properly considered as part of their responsibiltiy for the wrongdoing; it has nothing to do with the youth's personal responsibility.

You're not exactly working to build respect for the law when you create a system that treats juvenile partners in crime differently because some are rich and some are poor.