In Kenwood, palatial homes compete for space, tourists come to gape at the monuments to gracious living and the cherry trees are said to be more beautiful than in Washington. The people who live in Kenwood, a pocket of prime real estate nestled between River Road ad Bradley Boulevard in Bethesda, enjoy yet another advantage -- they have surprisingly few burglaries.

The were victims of only seven of the 96 residentials burglaries last year in the police beat that includes Kenwood, Chevy Chase and Somerset.

The 260 households pay for that enviable record, to the tune of more than $30,000 annually for the services of Captain Vincent Healy, a jovial 63-year-old private Pinkerton's, Inc. guard.

For four years, the "Captain," as neighbors know him, has cruised the streets in his white Malibu with the Pinkerton's Security Service insignia on the door, watching for strange cars and unfamiliar faces. He has never fun into a burglar, but the Kenwood neighborhood is willing to pay for the psychological and deterrent value of his presence.

"The main thing is continual driving, to be seen by the people of the neighborhood and others passing through. Seeing my car might cause some people to change their minds," said Healy, who puts up to 90 miles on his car over seven miles of neighborhood roads in a single shift.

Suburban burglaries have risen 36 percent in Montgomery County and about 11 percent in Prince George's from 1979 to 1980. While a private guard is one affluent community's answer, other neighborhoods in the two counties have formed watch groups, informal networks organized by block or street that police say can make a home seven times less likely to be burglarized.

There are more than 400 block groups in Montgomery County and about 75 in Prince George's, formed with the encouragement of the county police departments over the last three to four years.

Watch groups, or block watches as they frequently are called, are made up of the residents of a particular street or block who have exchanged telephone numbers and in some cases work schedules to agree to call one another and the police about suspicious activities.

"We all got unnerved by the fact that immediately surrounding streets had burglaries. It kept getting closer to our street," said Margit Beckman, who lives in Kemp Mill, a Montgomery community of about 1,200 spacious suburban homes along tree-lined streets. Last year, 73 burglaries in two months brought frightened residents together to form a watch group.

They met with a police officer to discuss home security, named block captains, drew maps with telephone numbers, and agreed to inform one another and the police of strangers around other people's homes.

"I try to memorize the cars that my neighbors have. I'm always watching and keeping my eyes open," said block member Dorothy Koplowitz. "If I see someone poking around a house, I call up the owners and ask them about it."

The first three months of this year, burglaries in the area were down 65 percent from last year. On one call from an alert neighbor, police arrested five youths burglarizing a home.

"One of the big problems with neighbors calling police about each other is that they don't want to look foolish and appear nosey," said Alice Lindsey, a Kemp Mill resident who hosted an organization meeting.

"We're asking them to be their brother's keeper," said Lt. Thomas Skaife of Montgomery County's Crime Prevention Unit. "Their eyes and ears are better than ours. To us, they're all strangers, but they know who the strangers are."

But neighborhood watch groups, which have been gaining popularity nationwide since the mid-1970s, are only as effective as the attention span of the neighbors. "When they're scared, you have their full-time attention," said Skaife. "But when it's quiet, languid, peaceful, attention wanes. It's natural. It's hard to keep checking the barn all the time when the horses haven't been stolen.

"I think it's one of the best ongoing programs we have. But you have to have group enthusiasm. We give the initial shot in the arm but it's up to the block captain after that."

Police say that most burglars hit between the hours of 10 a.m. and 2 p.m., and are teen-agers who live in or near the neighborhood. The number of those crimes is reduced easily by an active neighborhood group, although the effect is to send the burglars to an adjoining area, police say.

"A study in Bethesda a couple years ago showed that neighborhood watch groups tend to displace crime. You're forcing (burglars) to move to the next block," said Skaife. "Without watch groups, your chances of being burglarized are 1 in 38. With watch groups, it's 1 in 260."

Neighborhood watch groups are most effective in suburban or rural neighborhoods, and less likely to work in large apartment complexes.

In Clinton, in southern Prince George's County, for instance, Police Officer John Moss has seen a gratifying decline in burglaries and vandalism in many of the moderate-income neighborhoods.

"In Cheltenham Forest in Clinton, on the average there was a crime there one or two times a week. It doesn't sound like a crime wave, but to those people it's a lot," Moss said. After the neighbors organized, the crimes stopped completely.

"It's more than just arrests," he said. "It's the education of people.Neighborhood watch groups are like a large alarm system. Once you know what to look for, you have better witnesses and better prosecution rates. A lot of people didn't even know where the police station was."

In Hyattsville, however, the apartment complexes pose a problem.

"There's a lack of community spirit or purpose," said Prince George's Police Officer Mike Knapp. "But there's a limited amount renters can do. Part of it is the management. Management is very reluctant to inform renters of any crime problems. Security for buildings costs money and they're unwilling to pay."

Overall, police say neighborhood groups help. "In many of our neighborhoods it's almost eliminated what was a serious crime problem because the area gets a no-nonsense reputation," said Knapp.

Exclusive communities like Kenwood, however, worry less about vandalism and neighborhood troublemakers than about professional thieves. One resident stepped away for a couple of hours at noontime recently and returned to find $100,000 worth of silver and jewelry gone.

The community feels that hiring a private security company, at a cost of $175 per year to each of about 200 homes, is worthwhile, even if only for the psychological comfort of knowing the Captain is cruising about.

"The key is having one person you can really relate to," said Matthew Stone, president of the Kenwood Neighborhood Association. "He talks to everybody and everybody knows him."

Healy, who himself lives in a modest Washington apartment with his wife and has never been burglarized, checks the homes of people who are out of town, gathers up newspapers piled on doorsteps, keeps an eye on partying teen-agers who have gotten too rowdy, and in general is the community's watchman.

"Yeah, like a dream around here, isn't it," chuckled Healy as he swung his car around the corners and up the hilly streets. "They rent some of these homes, you know. One of the families told me the house next to theirs was for rent. 'Captain, it would be nice if you lived next door,' they said. You know what the rent was -- $2,400 a month! Well, I said, if you say it fast it ain't bad."