When she was robbed several weeks ago in her apartment building off Southern Avenue, Louise Anderson lost $200 in change -- part of the previous night's receipts from the Virginia restaurant she manages.

Less than two days later, Anderson was robbed again. Like the first robbery, the second theft occurred near her Forest Hills apartment. This time, the thief made off with her pocketbook.

That was enough for Anderson, a short, stout woman in her 50s who wears her hair in a tall beehive. "I am now absolutely paranoid," she said last week at a "security forum" attended by nearly 100 Forest Hills tenants. "I asked my husband... to get me my grandfather's shotgun. What else am I supposed to do?"

Anderson is not the only one scared by the recent rash of assaults, purse anatchings and burglaries at Forest Hills, a 300-unit apartment complex just east of the District line in Prince George's County. Those who live in the 25 brown-brick apartment buildings say their welltended neighborhood has become a no-man's land where young crooks prey at will on residents.

"It's not unusual for these kids to come up to somebody and just point a gun at them and get their pocketbook or wallet," said Cecilia Owens-Lee, the president of the Forest Hills tenant association."

Tenant association leaders said the group failed once before to start a "Neighborhood Watch," a police-endorsed program that officials say has curbed some crime in other parts of the county. But the association leaders also said recent robberies and burglaries in their neighborhood will probably spur the tenants to improve security at Forest Hills. In the past three weeks, there have been seven purse snatchings, eight armed robberies and two attempted robberies at knifepoint at the complex, according to the tenants.

Two other assaults occurred while a group of tenants planned last week's forum, and there have been more than 40 burglaries of apartments and storage bins since Christmas, Owens-Lee said.

"Things are bad again in this area," said Prince George's Police Cpl. Frank Kobilis, who has met four times with the tenants in the last few years.

"These people are in one of the county's highest crime areas: They're inside the Beltway," said Kobilis, a member of the Oxon Hill station burglary squad.

Kobilis said he has received an unusually high number of complaints about recent crime at Forest Hills. While concern about crime is on the rise in the neighborhood, a ranking Prince George's police official contends that the number of incidents is "about average" for a complex that large. In contrast to the statistics compiled by the residents, police report only six burglaries, three strong-arm robberies, one armed robbery and one purse snatching at Forest Hills over the last three months.

"That number is not out of the ordinary," said Lt. George G. Helmondollar, the chief investigative officer at the Oxon Hill station. Helmondollar said no arrests have been made in any of those cases.

Many of Forest Hills' residents work as secretaries, military officers, computer operators and nurses, some of whom are employes of the nearby Greater Southeast Community Hospital where last week's forum was held. Several tenants said the most frightening part of their day was the short walk to end from work.

"The time I was robbed, they pushed me down on the sidewalk," said one middle-aged woman who works at the hospital. "They just yanked my purse out of my hands. I lost all my credit cards, my money, of course."

Kobilis said women with pocketbooks made easy targets for the thieves, who appear to range in age from 15 to 25 who have attacked residents singly or in pairs. "When you carry a pocketbook you may as well put a bulls-eye on it," he said, "because that's what the little creeps are looking for."

Tenants say many of their attackers have fled across the District line, frustrating Prince George's police who are permitted to pursue robbers into the city only in extreme cases. The two departments cooperate on such cases, but arrests are difficult, Kobilis said.

Robert O. Petrie, 52, a Forest Hills tenant for the last 16 years, said he was assaulted two years ago as he strolled through the complex on a Sunday afternoon. The wouldbe robber broke Petrie's jaw, but dashed off when Petrie chased him. "I wasn't looking around me at the time," Petrie said. "I don't let people get that close now."

Police believe that high-crime areas along Southern Avenue -- which they describe as a corridor of heavy drug-trafficking -- are shifting constantly, Kobilis said. Recent police and community crackdowns in the Glass Manor section of Oxon Hill and near the senior citizens home just south of Forest Hills on Southern Avenue have forced criminals into other neighborhoods, he said.

Still, police say, the number of burglaries in Prince George's generally dropped dramatically in recent months after the creation of a special anti-burglary unit and the use of a new, computerized fingerprint file. Under the Neighborhood Watch program Kobilis is urging the tenants to start, 40 percent of Forest Hills' residents would have to mark their property with an engraving tool provided by police.

"It's stinkin' shame you can't go where you want to go or be secure in your own home," said Kobilis. "We are here to help, but we'll need your cooperation, too."

"This time around we have to make the neighborhood watch work," said Anderson. "Most of us here are pretty scared, but we're angry about what's being done to us. It's time to do something about it."