With his friend at the wheel, Charles Fantroy crawled into the back seat, lowered the passenger-side window, aimed the revolver and sent a stream of bullets toward the silver Ford and its passengers. One slug penetrated the windshield with such force it tunneled through a front-seat headrest, brushing past its target. It was that bullet that pierced the forehead of Dennis Ashton Jr.

Dennis, who was 7 years old, died two hours later.

"I punished [him] with a Four-Four," a witness heard one of the killers brag that night.

The "Four-Four" that killed Dennis two years ago was a Smith & Wesson .44-caliber magnum revolver, a potent weapon made famous in Clint Eastwood's "Dirty Harry" movies as "the most powerful handgun in the world." Several young men around Benning Road SE in the District kept the gun in a backyard hiding spot, where they could use it, then stash it again.

That weapon was one of more than 2,000 illegal firearms seized by District police that year, a fraction of the total circulating in the city. It is also a symbol of a troubling incongruity: Despite being one of the few jurisdictions in the nation to ban handguns, the District is among the most gun-ridden.

"The District of Columbia has the strictest gun laws in the country, and, nonetheless, we continue to be plagued by the accessibility of guns and gun violence," said Wilma A. Lewis, U.S. attorney for the District.

Federal and local officials here say fighting gun trafficking is harder than ever because drug dealers and others are constantly changing the way they buy, sell and hide their guns. They barter weapons for drugs, employ "straw purchases" by friends and relatives and increasingly share their guns with others, usually fellow members of loosely organized gangs known as crews.

"The schemes have become more sophisticated," said Patrick D. Hynes, special agent in charge of the Washington field office of the federal Bureau of Alcohol, Tobacco and Firearms.

Washington's history of fighting guns has always been complicated by its peculiar geography: a city that bans handguns surrounded by two states with plenty of stores eager to sell them.

Ironically, tougher laws in Maryland and Virginia--limiting buyers to one gun a month--may be partly to blame. The laws cut down on the large-scale gun traffickers who loaded their car trunks with guns purchased outside the District only to sell them on the city's streets. But the result has been to disperse gun trafficking into smaller transactions--one or two guns at a time--that are much harder to detect. "Death by a thousand cuts," said Richard Edwards, a former assistant U.S. attorney in the District.

In response to tougher federal laws mandating extra prison time for gun crimes, drug dealers in the past few years have turned to "community guns" kept in common hiding places. That makes dealers less likely to be found holding a handgun.

The "Four-Four" used to kill Dennis was such a gun. Law enforcement sources said it was bought legally in 1986 from a Forestville dealer, Realco Guns, which has been linked to more crime guns in the area than any other dealer--493 guns traced by ATF in crimes between 1996 and last year. The gun moved into the District not in a smuggled batch but as a single weapon. It passed from person to person before landing in the Benning Road community, where drugs and gang activity are rampant.

"It became known as the neighborhood gun," Hynes said.

The flow of guns into the city has been steady, driven by a thriving drug trade and fed by buyers who live outside the District, large networks of families and friends stretching into the Deep South.

A Washington Post analysis of an ATF database of crime guns indicates that just over half of the guns seized by police in the District were bought in Virginia and Maryland. Last year, about 29 percent of the District's crime guns originated in Virginia, 26 percent came from Maryland, 9 percent from North Carolina and about 3 percent each from Florida, Georgia and South Carolina.

Since the early 1990s, federal and local officials here have mounted a series of efforts to crack down on gun violence, with varied success. When gun arrests are made, D.C. prosecutors often drop the charges to get information about more serious crimes. In D.C. Superior Court, gun cases have declined from 626 in 1997 to 489 this year, said the U.S. attorney's office, which prosecutes most of its gun cases in Superior Court rather than in the federal District Court.

"Nobody's getting any serious time for gun violations in Superior Court," said Assistant U.S. Attorney Michael Volkov, chief of the gang prosecution section.

Unlike federal judges, those in Superior Court are rarely bound by mandatory minimum sentences and have much more leeway to discharge gun criminals without prison time, Lewis and other federal prosecutors said.

By contrast, some communities have created intensive anti-gun campaigns uniting businesses, police, prosecutors and advocacy groups.

Richmond's Project Exile uses local and federal resources to send as many gun criminals as possible to federal court. The program has led to 438 federal indictments in two years, compared with 267 for the District, which has more than twice Richmond's population.

Helen F. Fahey, U.S. attorney for the Eastern District of Virginia, credits the decision not to "deal away" gun charges and an effort to make sure criminals got the message. That message is backed by a $400,000 advertising budget, some of it donated by the National Rifle Association.

In the District, federal and local officials recently announced their own program, with stepped up federal prosecution, increased intelligence sharing among jurisdictions and school programs. But the campaign, which revamps an effort called Ceasefire, has just $75,000 in its advertising budget, far short of the needed $1 million.

Josh Horwitz, executive director of the Educational Fund to End Handgun Violence advocacy group, said Washington suffers from community and business apathy and a deep distrust of the police by much of the African American population. "This city has had a problem both with corporate caring and community coordination," Horwitz said.

In the midst of such drift, criminals have had time to adapt.

The Park Morton public housing complex off Georgia Avenue, where a task force of federal and local agents pursued a three-year undercover operation, provides a window into the circuitous paths guns take into the city. In the U-shaped complex, where an open-air crack and heroin market thrived and 17 homicides took place in five years, agents seized and traced 16 guns.

One of them was a Lorcin .25-caliber pistol bought from a Manassas gun dealer in 1995. After the woman who bought it accidentally shot herself in the leg, she sold the gun to a dealer in Fairfax County. The next day, the dealer sold the gun to a man who eventually was arrested in Park Morton, where he was staying with his girlfriend.

Another of the 16 guns, a Davis .380-caliber pistol, had been bought legally in 1992 from a dealer in College Park. The buyer sold it for $100 two years later to a friend who lived in the District. The friend said the gun was stolen from his home in 1995; the chief suspect was a Park Morton resident.

The gun was later found in a basement storage room. Agents also seized four others: a 9mm TEC-DC9 semiautomatic pistol, an AMT .380-caliber pistol, a Dickerson .38-caliber pistol, and a Sears, Roebuck 12-gauge, sawed-off shotgun. Those and other weapons in Park Morton had originated in Owingsville, Ky.; Leesburg, Fla.; Durham, N.C.; Forestville; Augusta, Ga.; and Rutherfordton, N.C.

The task force operation led to 20 indictments on drug, murder and firearms violations, but the agents had trouble linking the shared guns to a specific person or crime.

Law enforcement officials say they rarely recover guns in murder cases--at least three-quarters of the city's murder weapons are never found. One prosecutor said two dozen murder defendants had told him they'd thrown their weapons into the Potomac or Anacostia rivers.

"Who wants to be found in possession of a gun with a body on it?" said Assistant U.S. Attorney Teresa A. Howie.

One murder weapon with at least two deaths connected to it did end up in the hands of prosecutors. The gun had been bought in Maryland and ended up in Maryland but passed through the District as currency in a black-market bartering system.

It was an S.W. Daniels 9mm, model M-11, machine gun--fully automatic. According to court documents, two crack addicts broke into a house in rural Damascus in 1995 and stole the machine gun and two shotguns.

The thieves brought the guns into the District to Mark Anthony Pugh Jr., a 23-year-old who hung out with the "3500 Crew," a drug gang that worked the streets a few blocks from Park Morton, the documents said.

Pugh turned down the shotguns but traded $200 worth of crack for the M-11. Then he sold the weapon for $800 to Ralph McLean, 29, a bicycle messenger and drug courier.

Two months later, McLean used the M-11 to kill Cpl. John J. Novabilski, a Prince George's County police officer. Earlier, he had shot two District police officers with a different gun. And in May, three months after the machine gun entered the District, McLean used it to kill FBI agent William H. Christian Jr. in Greenbelt. In the gun battle with police that followed, McLean, hit by at least seven bullets, put a semiautomatic pistol to his head and ended his life.

Like the M-11, the "Four-Four" that killed Dennis Ashton Jr. began and ended its journey Maryland but only after cutting a deadly path through the District.

Its victim, who lived with his mother in a row house in Northeast Washington, loved playing basketball and riding his bike. Dennis was getting ready for third grade.

As he often did on Sundays, he spent June 29, 1997, with his father, Dennis Sr. They had hit balls at a batting cage in Alexandria.

Later, with two of his dad's friends, they stopped at a fast-food restaurant on Benning Road SE.

"It was a perfect drive-by situation," said Howie, who prosecuted the case.

A car pulled up to the parking lot, blocked the driveway and fired on them. Only Dennis Jr. was hit.

When his mother, LaTonya Smith-Thomas, received a call to rush to Children's Hospital, she assumed her son had broken a bone or a fever had spiked.

"When they told me that my son had been shot in the head . . . I could not believe what I was hearing," she later wrote to a Superior Court judge. "I remember the coroner's van pulling up . . . and the way that man looked at me, the way we looked at each other, I knew then that my son was dead."

When Fantroy, now 20, and his friend Bernard Coleman, 24, learned they had killed a child, they walked to a gas station, filled a milk container with gasoline and doused and set on fire their brown Oldsmobile Delta 88. That evening, Fantroy, the son of a retired D.C. police officer, passed the time by shooting baskets with his friends.

The two men were arrested a few days later. They told police they had a two-year-old grudge against one of Ashton Sr.'s friends, who had been sitting in the front seat.

Fantroy and Coleman pleaded guilty to the crime and are in prison, sentenced to 25 and 16 years, respectively. Even after confessing, they refused to say what they did with the gun.

Two days after the shooting, the gun was back on the streets, in the hands of 17-year-old Michael Burrell, who also had ties to the Benning Road neighborhood.

First, Prince George's County police caught Burrell with a .22-caliber revolver under the seat of a car he was driving with stolen tags. They sent him to juvenile detention.

An informant told District police that they would find another weapon behind the dashboard of Burrell's car. When questioned, Burrell said he had bought the .44 from a man on the street, but an informant said it was the community gun that killed Dennis Jr.

A little more than a year later, before his trial date, Burrell was shot in the head, not far from the parking lot where Dennis was killed.

Burrell died with little public notice, but Dennis's death has become a rallying point. His photo, a gap in his teeth showing through his smile, has gone up on subway platforms and local buses this month. With this child's face as its icon, the new Ceasefire program asks the public to report illegal guns.

"Dennis K. Ashton, Jr."

"Shot dead by a criminal with an illegal gun."

"Missing," reads the caption. "Forever."

Staff writer Ira Chinoy, database editor Sarah Cohen and staff researcher Alice Crites contributed to this report.

'IRON CORRIDOR'

Last year, the District of Columbia had six times the number of crime guns per capita as New York or Boston, according to data collected by the federal Bureau of Alcohol, Tobacco and Firearms. Many of these guns have traveled up the "Iron Corridor," a historic gun trafficking route stretching from Florida to Boston. After a three-year undercover operation in Park Morton, a public housing complex in Northwest, the ATF traced the origins of 16 guns it had seized there.

A sampling of the guns traced:

Origin: Forestville

Gun type: Sturm Ruger

Origin: College Park

Gun type: Davis .380

Origin: Owingsville, KY.

Gun type: H. Weihrauch .357

Origin: Manassas

Gun type: Lorcin .25

Origin: Gordonsville, VA

Gun type: Smith & Wesson .38

Origin: Pembroke, VA

Gun type: TEC-DC9

Origin: Durham, N.C.

Gun type: AMT .380

Origin: Rutherfordton, N.C.

Gun type: Sturm Ruger . 45

Origin: Augusta, GA.

Gun type: Sturm Ruger .44

Origin: Leesburg, FLA.

Gun type: Lorcin .380

CAPTION: Park Morton, 16 guns traced, 1997-1999

CAPTION: A Smith & Wesson .44-caliber magnum like this one ended the life of Dennis Ashton Jr., 7, in 1997.

CAPTION: Dennis Ashton Jr. represents victims of gun violence in the District's new Ceasefire advertising campaign, which asks people to report illegal weapons.