On foldaway chairs at dusk, a cluster of five elderly Mount Rainier neighbors chat about grandchildren, yard sales, retirement and, inevitably, crime.

Seventy-two-year-old Claud Brown tells how he was mugged on his way to a part-time job during Christmas week in 1976. Kermit Nelson, his 78-year-old neighbor, says he watched Brown being mugged -- he thought the boys were talking to him -- and Lillie Barnett, 72, another neighbor, says she believes there's a lesser chance of her being mugged if she doesn't carry her purse to the supermarket.

The others talk about a neighborhood legend, a World War I widow, the one who died two years ago a week after a "rascal" practically scared her to death, snatching her pocketbook as she stood on her front porch.

Old-timers in Mount Rainier absorb crime stories like hungry sponges. They may have had a serious encounter themselves -- or heard about one that happened to a neighbor -- as many as five or six years ago. Their perceptions of fluctuations in crime and in police protection are conveyed with news-breaking urgency in a community where 40 percent of the population is over 60 years old.

"I don't even like to open the apartment door after dark," said 77-year-old Agnes Grady, a widow for 13 years and a 16-year resident of Queenstown Apartments, where at least half the tenants are over 60. "I don't go out so that somebody can get a hold of me. I won't even go down here to the washroom. I'm afraid to."

When a cuckoo bird struck 4 in the afternoon, she said, "That's my company."

Middle America endures in Mount Rainier. Joe's barber shop, Scott's coin laundry and Bass's liquor store along the "strip" on Rhode Island Avenue cater to the mostly white, blue-collar residents of this 71-year-old community just a few feet across the District of Columbia line in Prince George's County. Grandfathers still tease their grandsons with water from lawn hoses in front of modest bungalows. Saturday yard sales are social gatherings. Yet, despite these amenities of suburban living, the quality of life for almost half of these residents is eroded by the uneasiness about crime.

Much of Mount Rainier's elderly population is concentrated in the 1,056-unit Queenstown and the 347-unit Queen's Manor complexes, where elderly tenants fill 50-to-75 percent of the apartments. They move to apartments like these from larger, more expensive homes when they retire, when all the kids are grown and married, when they are widowed and, in some cases, when the pluses outweigh the minuses of city life.

"I guess [I moved here] because I wanted to get out in the suburbs," said Ada Riley, who moved to Queen's Manor six years ago from Anacostia.

In 1976, responding to a campaign by Betterment for United Seniors (BUS), a vocal group of Prince George's elderly, county police set up a special program to combat an increase in rapes and muggings in Mount Rainier and neighboring communities that also have a large proportion of residents over 60.

As part of Seniors Against a Fearful Environment (SAFE), as the program is called, police began patrolling a 10-mile area on foot and on motor scooters and advising senior citizens of precautions to take against crime. Among the precautions were traveling in groups; installing dead-bolt locks on doors; not carrying large amounts of cash for large pocketbooks; trimming hedges around their homes that obstruct their view; and not opening their doors to strangers without proper identification.

Within a year after SAFE was started, there was a decrease in crime in the area patrolled by SAFE, according to Mount Rainier police records. Last year, however, for the first time since the program began, the number of purse-snatchings, the most common crime against senior citizens, increased, and SAFE officials expect a further rise this year.

"Just the idea of seeing these officers walking around gives them [the elderly] a greater sense of security, the confidence to walk to the store, as well as deters crime," said Mount Rainier Mayor Lavinia (Linda) Nalls.

Despite the program, some Mount Rainier residents continue to feel uneasy about the threat of crime in their community. "We used to have better [police] patrol through here than we now have," said Lillie Barnett. Glema Brown, her 69-year-old neighbor added, "It's rare you see anybody going through here unless they're in a car."

Though Cpl. James Huff, who supervises Project SAFE, believes it generally has been an effective program, he said the elderly do understandably feel they are more vulnerable to crime than others. "You have a child and you have a senior citizen -- both are helpless," he said. "It's healthy to have an exaggerated sense of fear [of crime]."

He also said he believes 90 percent of the crime against elderly Mount Rainier residents is committed by black males from Washington under 30 years old. Since 62 percent of Mount Rainier is white, there is a racial element to the fear that sometimes comes out in discussions of the past, before blacks began moving to Mount Rainier in sizeable numbers.

Not all of Mount Rainier's elderly are victims. Some have devised clever ways to fight back and win.

Betty Jolkovsky, 83, a resident of Queen's Manor apartments, described with undisguised pride how she foiled an attempted purse-snatching in June.

"I was going with my food cart loaded with groceries from the Giant on Queen's Chapel Road around the corner to the Drug Fair when two boys about 15 yers old and two smaller ones were pushing me against the wall, and the food cart was almost turning over. The thing that worried me was that my wallet was . . . visible. It had all my credit cards and my Social Security card."

As the boys pushed the cart into her body, she recalled, she collapsed against a wall and said to one of the 15-year-olds: "'I know your grandmother, and she wouldn't be proud of the way you're treating me. Would your grandmother be proud of the way she reared you?' I was so thankful he didn't ask me the name of his grandmother, because it was a lie. I didn't know his grandmother."

Fear of the young, especially teenagers, is common. "We have a lot of kids that go to high school around here," said 84-year-old Etta Rauch, who two years ago was pulled backwards down her apartment stairs by a purse snatcher. "When they come out, I don't go near them. You never know what young people are going to do today."

Most troubling of all is the seeming inevitability of becoming a victim.

"The fear of the elderly," said 76-year-old Margaret Chambers, a widow since 1931, "is that they might be next."