Tall and gangly with a mouthful of braces and clad in scuffed sneakers, blue jeans and a T-shirt, Gary looks like a typical suburban teen-ager.

The son of a prominent Washington attorney and once a straight-A student and baseball all-star, Gary lives with his divorced, Vassar-education mother in one of Northern Virginia's affluent neighborhoods, an area of $150,000 homes.

But Gary is not typical. He is a convicted burglar who was placed on probation last year after he admitted breaking into a neighbor's home at night with a friend.

"The house was dark, the opportunity was there and we just did it," said Gary during a recent interview in his family's living room, which was decorated with antiques and Oriental rugs.

"It was, like, there wasn't much to do.And because it was the first time, I knew there was no danger of my going to jail," he said, flicking a cigarette butt into the fireplace. "A lot of kids know that, and a lot of kids break into houses just to see if they can do it."

Gary is one of an estimated 21,000 Washington area residents under age 18 -- more than 4,000 from Northern Virginia -- arrested last year for crimes ranging from breaking and entering to murder.

"You have some kids who are legendary, who've been in court 15 times and nothing has happened to them," said Fairfax County prosecutor Robert F. Horan Jr. "Word gets around at school, and that hurts us.

"I think because the court is closed to the press and public some kids think they're in this protected little environment where nothing will happen to them," he said.

Unlike adult criminals, who are often jailed for the same offenses, 96 percent of juvenile criminals in Virginia are put on probation and remain with their families in the community. This is despite estimates by Northern Virginia police that half of all reported burglaries are committed by juveniles.

Unlike juvenile crime in the District, which tends to be more violent and more motivated by poverty and unemployment, juvenile offenses in the affluent Washington suburbs are overwhelmingly property crimes committed by youths who do not need money.

The typical suburban juvenile criminal, according to authorities in Virginia and Maryland, closely resembles Gary. He is a 15-year-old while male who commits an amateurish burglary of a home in his own neighborhood, often during the day and most frequently during the summer.

He may be drunk when he commits a crime and often takes cash, steroes, cassette players, guns or liquor, but leaves jewelry or silver that are harder to sell. Because he is amateurish and may brag about the crime to his friends or classmates, he is more likely to be caught than is an adult thief.

He is probably from a single-parent family or a family rent by marital conflict. He may have a learning disability and be chronically truant or in severe academic trouble.

Last week, Gary's 14-year-old brother was arrested at a local recreation center on a maijuana possession charge.

"In Arlington, a juvenile charged with a crime is as likely to be a general's son as the son of a maintenance worker," said veteran Arlington police officer Delores Brown. The 1950s stereotype of a juvenile delinquent with a greasy ducktail haircut, black leather jacket and an armful of tattoos is outmoded, she said.

Whlie urban delinquents are traditionally regarded as street-wise about the legal system, local law enforcement officials say they affluent suburban juvenile offenders are displaying an increasingly sophisticated knowledge of their legal rights and of the weaknesses in the juvenile justice system.

"Word just gets around," said Gary, who added that at his high school "a lot of kids" know that few juveniles are committed to reform school -- now called learning centers. Many, Gary said, are savvy about legal technicalities -- what constitutes a lawful seach by police officers, for example -- which would have confounded teenagers a decade ago.

Despite the hundreds of millions of dollars spent annually on juvenile justice -- $50 million in Virginia alone -- juvenile crime remains an often studied and little understood problem, particularly when committed by affluent youths.

Although the juvenile crime rate has dropped slightly since 1975, a 1978 Ford Foundation report shows that youth crime has tripled since the early 1960s.

Between 1976 and 1978, juvenile arrests in Northern Virginia, according to a regional planning agency study, increased 80 percent for burglary and 44 percent for larceny and theft, an increase officials attribute in part to a major overhaul of the state's juvenile code.

"One of the things people underestimate is that crime is exciting and a lot of kids think that their lives are boring," said David Luria, a former juvenile prosecutor in the District who now defends youths as director of the Antioch Law School Juvenile Justice Clinic. "Crime is a high and for a lot of kids, a rite of passage. These days there's not much social stigma among kids attached to being in trouble."

"There's a desperate desire for easy solutions," he continued. "The problem is that there's no coherent philospophy of juvenile justice because nobody knows what to do. Just throwing money at the problem won't help."

But that's precisely what many affluent parents apparently do.

"A lot of parents would rather give the kid a $20 bill and the car keys rather than 20 minutes of their time," said Carl Beyeler, administrator of Arlington's juvenile court, which last year processed 1,400 juvenile delinquents.

"Around here kids have too much money, too much free time and too little supervision," said a Fairfax County detective. "A lot of parents are busy with their own careers and ragard the child as an inconvenience. I see 12-year-olds who have no curfew, come home at midnight drunk and their parents don't say anything."

Gary was arrested at his home in the early evening less than an hour after he and a friend walked to a nearby house on Gary's paper route, slit a window screen with a pocket knife and climbed into the house.

The neighbor came home during the burglary. Gary ran out the back door to his own home but his friend was caught inside the house, in possession of several packs of the owner's expensive, imported cigarettes. The police arrested Gary a short time later.

"We were looking for little things, stuff we could carry easily, not like stereos, I don't really know what," said Gary, who was earning $100 per month as a paper boy at the time and says he did not need more money.

In the parlance of juvenile court, Gary pleaded "not innocent" to the charge and was placed on indeterminate probation, with the condition that he see a psychiatrist.

His probation officer imposed a curfew, which his mother says he has violated three times: he must be home by 9 p.m. during the week, 10:30 p.m. on weekends.

Gary, who at his mother's insistence paid his $250 attorney's fees and wrote a letter of apology to the victim, says he regrets the burgulary "because the curfew stinks."

"Of course, if I'd been him (the victim) I would really have been mad," he said. "I would probably have broken a bottle over (my friend's head) or something," he said.

"Gary's arrest was just a total shock," recalled his mother, a housewife who suffers from pancreatitis, a painful digestive disorder. She supports herself, Gary and his younger brother on monthly alimony payments of $1,500. She and Gary's father were divorced last year after a bitter and protracted separation marked by what she describes as vicious custody battles.

"Everyone kept asking Gary, 'Why did you do it?' and no one ever really got an answer," she said, sipping iced tea and chain-smoking unfiltered cigarettes.

"I remember telling him on the way to the police station, 'How can you be involved in a goddamn dumb thing like this when you know I'm in the middle of a custody fight with your father?'" she said.

"The psychotherapist said that he was depressed and had not accepted the divorce and that this came out in a hostile act like the burgulary."

Gary's mother said that the first sign her son was having problems came shortly after the separation when Gary skipped school twice and spent the day at Tysons Corner. This year he has skipped school so often that he may not pass, although he is earning honors in a foreign language program.

"My kids have never been allowed to drift," she said, "I let them go out if they had a specific destination, and I checked were they were. The allegation by [the probation officer] was that I supervised them too much."

When her younger son was arrested last week, she said, "I spent a day being hysterical about that, but mostly what I feel is befuddlement. I really don't know why things went bad, why I've got two kids in trouble."

"One of my biggest regrets is that I didn't get both kids into therapy sooner," she said. "Basically I find it unproductive to lie awake at night gnashing my teeth over what I could have done differently."

While Gary's mother says she feels her son has generally received fair treatment from juvenile court officials, Gary is openly bitter about his experience.

"All those lawyers in juvenile court are on a first name basis with the judge and they won't stick up for you at all, they just want you to plead guilty and not make the judge angry," he said. "I think the whole system is corrupt and I just wish people would leave me alone."

But critics of the juvenile court system say that too frequently juveniles are left alone, repeatedly sent back to their parents and the community where they become more skilled at committing crimes which go virtually unpunished.

While statistics on repeat offenders are sketchy, estimates are that between 20 and 40 percent of juveniles tried annually in Northern Virginia have been through the courts previously on delinquency charges.

"A lot of kids -- both rich and poor-- don't think that what they're doing is wrong," said Arlington police youth resources chief William Jeunette. "They have a million justifications for what they do.

"The biggest problem is that these kids are repeatedly told, 'If you do that again I'm going to send you away' and that never happens," he said. "These kids learn the system fast and know what they can get away with."

Earlier this month, Arlington prosecutor Henry E. Hudson announced that he would attempt to have certain repeat offenders, particularly burglars, tried as adults in open court rather than in secret juvenile proceedings. In order to do that, prosecutors must successfully petition for transfer of trials to circuit court.

Area juvenile court officials and judges admit that the system has flaws, but insist it is functioning.

"What we do is not very well understood because we're closed to the public," said a Northern Virginia probation supervisor. "Our mission is different -- we're here to help the kid and get him out of the court system as fast as possible."

Juvenile justice experts say that the prosecutors' criticism illustrates one of the central conflicts in juvenile justice: the delicate balance between protecting the community on the one hand and rehabilitating the child without incarceration on the other.

"Some people just want a whole lot more punishment out of kids than others," said Kathy Mays, a senior analyst with the Virginia State Crime Commission in Richmond. "In general, the public thinks that juvenile criminals are little sons of bitches who should be locked away. But you can't stereotype juvenile criminals any more than blacks or women."

"The public also wants instant results, even though it took 14 years for a kid to become a criminal," said Mays.

"We see a lot of parents who are just so out of it that they can't help their kids, they need help so badly themselves," she said. "And let's face it, in this society it's a lot easier to have a baby than it is to get a driver's license, so some of the root causes aren't going to go away."

Mays and other observers say that one of the classic weaknesses in the juvenile justice system is that there has been little emphasis on preventing juveniles from committing crimes.

"A juvenile court is kind of like a hospital," said Beyeler, Arlington's court administrator. "The one thing you put in a hospital is a morgue because some patients are so infected with disease that they're not going to make it. That's exactly the way it is here. Some kids come in here so tied up in knots or with such faulty parent-child relationships that they're not going to make it no matter what."