On Sundays, while many residents are in church, real estate speculators drive through the run-down areas of Shaw and 14th Street NW, checking out their properties and future investments. Many in the neighborhoods find the visits unsettling.

"You can see them scoping out the area in their Mercedes and BMWs," said Ibrahim Mumin, a Shaw neighborhood activist who, like many of his neighbors, is afraid that new development will drive out longtime residents and merchants. "There are tremendous external pressures we can't control in our neighborhood."

But where Mumin is fearful, Marvin Jawer is elated. A lawyer-developer with millions invested around 14th and U streets NW, he is reaping hefty profits building small shopping centers in place of boarded-up stores and empty lots. "This is a unique opportunity that can't be missed," he said.

Twenty years ago, when riots destroyed huge stretches of stores and restaurants along 14th Street, as well as Seventh Street NW and H Street NE, much of the city's white business community got the message it was not welcome anymore. Hundreds of business owners, burned out or not, left for the suburbs.

Government officials spent the next 20 years trying to rebuild these key retail streets. But there were many obstacles -- investors' skepticism, unpredictable government behavior and squabbling community groups.

Until now. There has been a dramatic turnaround in the past three years. Investors such as Jawer, for the first time in a generation, see profits on the streets that burned.

"It's payoff time," said Larry Press, a top D.C. government planner who has promoted development in the riot areas for 20 years.

Press and other officials, while decrying the riots' destruction, said that at least the uprising gave government an opportunity to clear some horrendous slums.

Rebuilding, however, proved difficult on the approximately 1,000 properties, many of which were damaged in the riots and acquired by the government. Press recalled scathing newspaper editorials denouncing delays in redevelopment then. "Now, after 20 years," he said, "we can look back and say, 'This is what we've done.' "

What they've done is not obvious to first-time visitors.

These areas still look beat-up, with boarded-up buildings, broken glass, garbage tumbling in the wind, and vagrants and drug dealers. There is the appearance of urban hodgepodge. Each has longtime stores that survived 1968, next to empty lots where competitors once stood, with a sprinkling of rehabilitated and new apartment buildings, plus the newcomers -- the new shops with bright awnings.

The word mentioned by many people in these neighborhoods is "waiting."

Around Seventh Street NW, they wait for repairs to the rickety, city-owned Howard Theater on T Street, once a showcase for top acts. On 14th Street NW, they wait for word about plans for single-family homes on the site of community gardens at Clifton Street. On H Street NE, they ponder the future of the decrepit Liberty Cab building at Sixth Street.

The story of the waiting game is told downtown in the computerized files of the D.C. Recorder of Deeds. They show that since about 1985, key tracts in all three riot neighborhoods -- especially those near station sites along Metrorail's planned Green Line -- have zoomed up in value in anticipation of development.

Some storefronts in Shaw, selling about three years ago for $20 a square foot, now sell for four times that.

Like Mumin, many activists fear rising rents and property taxes will push out residents. They foresee their areas as hot spots for young professionals, mostly white -- the new Dupont Circle.

Mayor Marion Barry said he sympathizes with the longtime residents, who are mostly poor blacks.

"People feel threatened," Barry said. "They don't know at what point the landlords are going to put them out and renovate the house for some white person."

Some insiders believe the racially charged gentrification issue holds peril for Barry. Although Barry's heart may be with longtime residents and merchants, his head -- and his tax experts -- tell him that the District needs redevelopment's tax revenue.

Barry brought the trouble on himself. D.C. government, criticized so long for inaction, now can take some credit for helping spur the rejuvenation.

Developers believe that, besides Metro's role in promoting investment, recent successes in the riot areas are the result of the D.C. government's coming together with various parties often in conflict: bankers, who for years were accused of "red-lining," or refusing loans for projects in those areas; community groups that put aside back-biting ways; and young, risk-taking developers who were in adolescence when the riot areas burned.

These young entrepreneurs aim to make money off a market largely unexploited since 1968 -- retailing in poor sections of town.

It's a Boom Business'

The riot areas were three of the city's most bustling black shopping areas. The looters, without realizing it, were condemning themselves to a generation of inconvenience. Hundreds of people in the riot areas still have to take a bus just to fill a prescription.

Jawer and his partners have built or planned 1 million square feet of retail space, including 15 Peoples Drug Stores, in the area's run-down neighborhoods.

Their formula is to build small shopping complexes about every six blocks on D.C. streets hurt by merchants' post-1968 exodus.

Their banker, American Security Bank Vice President Karen Kollias, summed up their philosophy: "Just because you're poor doesn't mean you don't buy food."

Other bankers have played a role, too.

Barry and D.C. Council member Charlene Drew Jarvis (D-Ward 4), who oversees banking legislation, a few years ago began pressuring banks to make loans in low-income areas.

Now lenders are falling over each other to find credit-worthy projects in poor areas.

But many agree the most successful is Kollias. Before joining American Security in 1986, she spent 18 years as a street-level gadfly for development, including work with activist priest Geno Baroni.

She is considered one of the city's experts on inner-city development.

"Lending in District neighborhoods was an untapped market," she said. "Now it's a boom business."

Community groups also have become key players. City officials virtually require developers in low-income areas to take such outfits as partners.

Many groups have a history of infighting and hostility to business interests. Now some community groups, changed with the aid of foundations and the city, are lugging around architects' drawings and negotiating loans.

The three-year-old H Street Community Development Corp. is an example. A predecessor group had been criticized for not accounting for funds. So the first action of the new group's director, William Barrow, was to set up an accounting system.

"You play it straight and account for every nickel," said Barrow, a law school graduate and former accountant.

Barrow, whose group is a 52 percent partner in a new office complex on H Street NE, said he doesn't seek investment out of charity, but out of business sense.

"Emotionalism is not what sways these guys," he said.

The D.C. government has played various roles in these transactions, including therapist for skittish participants, lender of last resort and wheeler-dealer.

One deal caused controversy because of the developer's friendship with Mayor Barry: the city's 1985 purchase of Shaw land from Jeffrey N. Cohen, a complex $12 million transaction that also included a Mumin-led group as partner.

D.C. government's other deals have not generated as much news, but the city has improvised similar incentives for developers. The best tool in the District's shed is offering discounts on city land, much of it acquired as damaged property after the riots.

Will Jackson, a top city development official, said all parties are learning.

"The neighborhoods and the city matured together," he said.

The growing-up process hastened with the anticipation of Metro's Green Line, the first segment of which is expected to open in 1990.

Land speculation around the four Metro station sites in the riot areas -- and the waiting game -- have become intense sporting events.

Metro has brought billions of dollars in investment to the Washington region, prompting office booms in once-sleepy suburbs such as Ballston, as well as downtown. But the Green Line is the first to test Metro-generated growth in the inner city.

Industry officials disagree about the prospects. Some, such as Kollias, believe Metro's benefits are exaggerated. Many investors, though, are backing their hunches with cash.

The increased speculation near Metro stations is the reward for a decision made 20 years ago.

Until April 1968, Metro had planned its Green Line to head up 13th Street NW to a Columbia Heights station before turning east. But within days after the riots, Metro officials, knowing the rail line's development potential, hurriedly rerouted the subway along the riot areas -- up Seventh Street NW, west at U Street NW, then up 14th Street NW.

That decision could bring tens of millions of dollars in investment and jobs to the riot zones. And, given the increasing tendency toward "reverse commuting" -- D.C. residents working in the suburbs -- it will give residents convenient access to the region's jobs.

The Promise of Metrorail

Of the four planned Metro stations in the riot areas, the one likeliest to spur dramatic growth is near Mount Vernon Square.

Rows of small stores still stand on the east side of Seventh Street there, but the west side -- where competitors once stood -- now is mostly vacant lots. Office complexes are expected there, in line with the office boom nearby in downtown.

Experts say it's harder to tell what will be built farther up Seventh -- a snaggle-toothed collection of run-down stores, housing projects and messy Metro construction yards.

Tuxedo Valet dry cleaners, operated there by Edward Archie for 41 years, survived the riots.

Archie said he hopes his years in the depressed area since then will pay off once Metro's Shaw station -- "our hope, our dream" -- opens nearby.

Archie's experience sums up that of thousands of people in these neighborhoods who have held out bravely against the crime and the drug dealers, and don't want to give up just before the turnaround.

Archie said speculators continually ask to buy him out. While he refuses, he's afraid these men someday will cheat him out of his property.

"We're afraid of big business, the big bucks taking over," he said.

Several blocks northwest, where Metro plans its U Street station, Barry helped some merchants' chances for survival by importing city workers. A $50 million municipal building, finished in 1985, houses offices for 800 D.C. employees. The complex prompted construction of other office projects, and developer Cohen's plans for a $200 million office-residential complex nearby.

In addition, it helped inspire creation of a new 14th Street performing arts district, where seven theaters within six blocks draw hundreds of patrons some nights.

Another theater, the Tivoli, is key to the hopes of Columbia Heights, where another Metro stop is planned. For years, preservationists have stalled rehabilitation of the 67-year-old former vaudeville house at 14th Street and Park Road NW. But a recent settlement may allow developers -- including investor Herbert Haft -- to begin building offices and stores there soon.

Developer Edward Kassoff said he believes rebuilding the Tivoli will bring a "renaissance" to the area. Kassoff is selling new, two-bedroom town houses nearby for $125,000, mostly to childless young professionals. With several rehabilitation projects nearby, Kassoff said, "this area recently has changed dramatically."

But everyone agrees that of all the riot corridors, H Street NE has seen the most dramatic change.

Among the streets that fell in 1968, its decline was perhaps the most tragic. Once the city's second-busiest retail area after downtown, it soon took on a look of urban death, with drug users running wild where families once window-shopped.

R.J. Turner, a real estate broker who fixed up properties there several years ago, recalled that when he brought prospective investors, they sometimes found drug needles on the curb.

"It didn't instill confidence," said Turner, some of whose properties were foreclosed on.

"I sank my teeth into H Street," he said, "and broke a few."

Dr. Arthur Williams, an oral surgeon and community activist, said H Street hit bottom about 1985, after the Safeway at Sixth Street closed. "That was the last straw."

Ironically, that was around the time things started looking up.

The Barry administration, using the same tactic as on 14th Street NW, planned D.C. government offices there. The complex, which will house offices for 900 D.C. workers, will open within months.

The new Mega Supermarket opened next door last month. It joined other H Street projects that opened recently, such as an 18-store shopping center.

Real estate specialists believe one reason for H Street's rebound is the rehabilitation of old row houses just to its south, as more young professionals venture from gentrified Capitol Hill.

"H Street's gone like skyrockets," said Kollias. "There's nothing we couldn't do."

The improvements are gratifying to many people, including D.C. Del. Walter E. Fauntroy, who gained fame trying to bring changes to Shaw, his childhood neighborhood and the location of the New Bethel Baptist Church, of which he is pastor.

In the mid-1960s, Fauntroy organized a plan to redevelop the area by avoiding the mistakes of 1950s federal urban renewal in Southwest Washington, where poor blacks were moved from their homes to make way for whites.

Fauntroy and his group wanted to rehabilitate Shaw for the residents themselves, and to buy out slumlords. He called his plan "nonviolent land reform." But most people said he was dreaming.

Black Churches' Influence

That is, until April 1968. Fauntroy and D.C. officials realized that the hundreds of postriot empty lots presented an opportunity for his plan.

"The riots cleared the swath that became the starting point," Fauntroy said.

Officials later implemented some of Fauntroy's ideas by pouring hundreds of millions of dollars into the riot-scarred areas, treating them almost as disaster zones.

The federal government -- and then D.C.'s new government, under Mayor Walter E. Washington -- planned repaving of streets, rehabilitating houses, improving street lighting to discourage crime, and building new parks, schools and libraries.

But almost the only large-scale development in the riot neighborhoods from 1968 until recently was undertaken by black churches.

The churches were essentially the areas' only stable organizations, and the only ones able to take advantage of federal housing money offered to nonprofit groups.

The churches constructed more than 4,000 units of low- and moderate-income housing.

Meanwhile, the city tried desperately to attract private developers. But they weren't interested because they didn't see a way to make money in the riot areas, and they foresaw trouble with officials and community groups.

Federal and D.C. agencies -- atoning for their past arrogance in Southwest -- ordered city officials to patiently hear out community groups' demands, however unreasonable.

The groups often split into bitter factions. Officials recall wasting years sorting out street organizers' demands for government money.

"There's a feeling now that this was 'keep quiet' or 'keep people happy' money," said longtime D.C. planner John Fondersmith.

Hopes dimmed further in the late 1970s, as the federal government cut funds, then cut more in the early 1980s. Residents said these were the riot sections' darkest years.

As long as these neighborhoods depended only on government money, they were going to continue to shrivel, analysts said.

But that's what has changed recently, they said.

"If you want to see the inner city rejuvenate," Shaw developer Robert Branson said, "have people do it who can make money at it."