Marvin Bowser had no sooner moved into North Lincoln Park than he found out his house was within blocks of a bustling drug market.

When he heard there was a neighborhood anti-crime patrol, he signed up immediately.

For the next year, he and a group of neighbors spent two hours a night, six nights a week, walking the streets around 14th and D streets NE, using intimidating stares and calls to police about suspicious cars and activity to prod drug dealers into moving along.

Their presence has made a difference, Bowser said. But it has not come close to ridding the neighborhood of illegal drugs and probably never will, his colleagues said.

Last summer, the nightly patrol disbanded.

"We hit a plateau as far as getting results. It was just a hassle," Bowser said. "It was like a big joke . . . as soon as we slacked off, they started coming back like cockroaches."

Police and city officials hail the neighborhood patrols, bands of residents who often wear matching baseball caps to identify themselves, as key to the city's war against drugs and crime.

Altogether, officials estimate that more than 6,000 residents participate in the patrols. And the city's new drug czar credits them with helping close half the city's 90 open-air drug markets.

Since the first patrol started more than two years ago, nearly 100 similar groups have organized across the city. But now many also say they are struggling to keep going.

"Things are not the way they were last year. Unfortunately, it sort of has dwindled down," said Patricia Barnes, an organizer of the Parkside Terrace Coalition, which until recently actively patrolled the 291-unit apartment building at 3700 Ninth St. SE. "It happens in most organizations, when the same people are coming out in full force, they get tired."

"I'm tired of pushing my neighbors and hearing everybody making excuses," said Charlie Gaynor, who helped organize a patrol on S, Swann and T streets NW. "I've got a life, too."

Mostly, it is getting harder to recruit volunteers, said Carolyn Saunders, an organizer of the year-old Parkview Coalition in Northwest, who she said is down to about 10 faithful members. "We started out with 27."

Other groups have just given up.

"We had a hard time getting more people involved," said Christine Leake, chairman of the Second Northwest Coalition, which until last summer patrolled the area around Fifth and O streets NW. "You couldn't get enough people to cover each corner."

Vicky Salin, who organized the Capitol Hill East Coalition, which walked the neighborhood from January to May last year, said her group was successful in getting one block cleaned up, then broke up because of internal conflicts. "People couldn't get along with each other," she said.

Organizers said the problems are inherent to any local organization.

"It's not that every group must grow. Some grow and some fall off. The main thing is that you have people on the street," said James Foreman, the coordinator of the Metro Orange Coalition, which has organized thousands of District residents to participate in more than 60 neighborhood patrols. "Ninety percent of our groups are still on the street."

It has been two years since the first orange hat patrol was organized in Fairlawn, and Foreman said the volunteers in their signature orange baseball hats have helped close more than 200 crack houses and pushed countless drug traffickers off neighborhood street corners.

"I would not have thought two and a half years ago that we would have as many people out participating as we do," said Cynthia B. Harris, the special assistant to the mayor for drug control policy.

Carrying flashlights and crackling walkie-talkies, the group members emulate tactics used by the Nation of Islam to eradicate drugs from the Mayfair Mansions complex.

Their methods range from congregating on street corners keeping watch on prospective customers to complaining to city officials en masse about suspected crack houses. Using floodlights borrowed from the National Guard, they illuminate dark alleys where drug users congregate.

Some are more aggressive, using metal cutters to sever the receivers of public telephones that dealers have been seen using for business. To keep dealers away from some corner buildings, other groups have painted ledges and walls with a heavy-duty sticky substance that clings to anyone who leans against them. Some say they even have dumped dog feces in narrow alleys between houses to keep drug runners from using them as getaways and stashes.

Along the way, some say they have also taken their share of abuse. Groups citywide complain of having rocks and eggs thrown at them, shots fired over their heads and their vehicles vandalized. Nightly, they say, they are verbally harassed, taunted with names such as "tattletale" and "pumpkin head" for their orange hats.

Organizers tell stories of members whose children were threatened because of their activities, of customers who got out of their cars and went after them and of finding intimidating signs tacked on participants' doors.

Still others tell of new members who infiltrated their organizations to tip dealers to patrol activities.

"It's happening all over," said Albert Pearsall III, who walked with both the Elvans Road and Washington View patrols, which are both now virtually defunct. "It wears on people when you get threatened."

But diehards persist and have even expanded their mission to include other outreach projects for local residents.

"We're out whether it's raining, snowing or shining," said Leroy Thorpe, who organized the District's first patrol in Shaw. That group patrols only one night a week and makes do with a small core of members -- partly because it has been so successful.

"If we don't do it, nobody is going to do it," Thorpe said. "By whatever means necessary, we've got to get the job done."