In the Northeast neighborhood where 15-year-old Sean Smith was shot to death Monday, some teen-agers accept the use of guns as a way to settle arguments.

"Why would you fight somebody when you can shoot 'em?" a bespectacled youth, 16, asked incredulously. "Instead of fighting, it's easier to shoot."

"If you fight, you could be up there all day," said his friend, a teen-ager dressed in a raccoon-fur jacket. "You could just shoot 'em and get it over with."

Both youths, who would not give their names, said they don't carry guns, but would, one said, if "someone was looking for me."

The proliferation of illegal guns on the streets in some D.C. neighborhoods, especially where drugs are heavily trafficked in, has spawned a new mentality in which the status symbol of firepower in some cases appears to outweigh the value of human life.

"There's something that's happening that defies anything that we can understand at this point," said Isaac Fulwood, assistant D.C. police chief. "There's a psychology in a lot of these young people. They don't place any value on life." The mentality, he said, is that you "can shoot somebody, go home and go to bed."

The signs are everywhere: A teen-age girl watches boys in her neighborhood gather regularly to show off their guns and blast them in the air. A young former Marine sees teens carrying weapons "that aren't to be believed." An emergency room doctor at a Southeast hospital spends nights fighting to save the lives of young men riddled with bullet holes.

Many of them don't make it.

Monday night, 15-year-old Sean Smith of Northeast Washington was shot to death in an argument over his new red ski jacket.

On Dec. 17, 12-year-old Mark Settles was shot to death in his Southeast home, along with his dog. Kendall Merriweather, 17, was shot to death on a Southeast street corner when two teens tried to steal his boom box radio.

On Sept. 25, the body of Derrick Ingram, 16, was found. He had been shot twice in the head; his wrists were handcuffed behind his back.

Last year, 62.5 percent of the 227 homicides in the District were committed with guns and 57 percent of the killings have been drug-related, police said.

The year's total includes 19 homicides of juveniles, in which 14 of the victims ranged in age from 11 to 17. Through Nov. 30 of last year, 199 juveniles were the victims of assaults with guns.

In a statement released yesterday in which he asked for the public's help, Police Chief Maurice T. Turner Jr. said, "Where years ago an altercation between two kids might have resulted in a fistfight, today young men caught up in the drug trade can easily afford to arm themselves with guns and, as tempers flare, chances are that those weapons will be used with more devastating and deadly results."

Although gun possession is illegal in D.C., youths interviewed around the city said that even if they don't own a gun they know where to go to borrow one, buy one or rent one from a friend.

Police and federal firearms agents say that a "hidden market" for guns has sprung up in tandem with the area's flourishing drug trade. The guns, which often are untraceable, can cross state lines from Maryland or Virginia to the District, and are passed from one pair of young hands to another.

"My uncle sells guns. Uzis cost $400 and .22s cost about $80," a boy, who said he was 12 years old, revealed before a friend told him to be quiet, as they shot pool at the Bald Eagle Recreation Center on Joliet Street in Southwest Washington.

"On Orleans you can buy guns and drugs," a 14-year-old youth, holding a boom box radio, whispered under his breath as he stood with friends at the corner of Sixth and I streets NE. "They shoot over there on Orleans Place every night."

Orleans Place, one block of mostly vacant and boarded-up row houses, is about 10 blocks from where Sean Smith was shot.

"You can exchange crack for guns," said a girl, standing outside an apartment building on Galveston Street in Southwest Washington, and who said she was 13.

D.C. police and agents from the federal Bureau of Alcohol, Tobacco and Firearms (ATF) say that the guns make their way onto the D.C. streets and into the hands of a hard-core criminal element through many channels, all of them illegitimate.

Gun possession is illegal in D.C., except in limited cases when licenses are granted, but the rules of possession are more lax in Maryland and Virginia, officials say.

Some of the guns confiscated by D.C. police are traced to gun shops outside the District. Some are stolen in crimes such as burglary. The guns move from hand to hand so often within the hidden market that they become untraceable. Sometimes, a gun's history can be traced only by its use in a crime.

The Derreck Ingram homicide, for instance, went unsolved for weeks until a 9mm pistol turned up that matched the bullets that killed him.

Police said they found the gun in the car of a D.C. man, Anthony Jerome Lindsey, 21, who was gunned down Dec. 14 in Capitol Heights. A police source said that Lindsey, whose nickname was "Black," was a known "enforcer" or hit man for a faction of drug dealers. With his death and the recovery of the gun, police closed the Ingram case, the source said.

Like Fila tennis shoes, gold Rolex watches, 4x4 vehicles and fistfuls of gold jewelry, guns -- especially 9mm semiautomatic pistols -- have become part of the "costume" of many drug dealers, said Lt. Samuel Prue of the D.C. homicide unit.

"A gun for the young drug dealer is part of the costume, the scenario. It's a necessary tool of the trade. You can't do drugs out there on the streets unless you can protect the drugs, the cash and each other."

Some drug dealers have so many guns that they rent them out on a daily or weekly basis, law enforcement officials say. Word of their wares moves quickly among those in the street culture and there is no shortage of customers.

"It could be a sideline," Prue said. "He could be a drug dealer who has so many guns to protect his normal business that he branches out."

It would appear that more and more guns are finding their way onto the street. But George Rodriguez, assistant special agent in charge of the ATF Washington field office, said that may not be true.

"Yes, there is an increase in violence and there are more firearms being violently misused, but there aren't any more firearms on the street in the District of Columbia today than there were six years ago," he said.

Increasingly, the violence in some neighborhoods is affecting law-abiding residents who are trapped because they live in areas preyed upon by hustlers.

"I don't carry one, but I got grazed by a bullet once when I was at Cheriy's" go-go club in Southwest, said Dennis Washington, 15, as he walked down Martin Luther King Avenue in Southeast. Washington attends Ballou High School, where Kendall Merriweather was a student.

"I don't know where to get a gun, but it wouldn't be hard to find out," he said.

"We live in an area where there is a lot of shooting," said the 13-year-old girl, who said she lives on Montana Avenue NE, a well-known drug corridor.

"It frightens me," she said. "I've seen one person get shot, but we run inside. Usually it's over money and drugs. Most of the guys are about 15."

Eric Prater, a 25-year-old former Marine who now works as a tractor-trailer driver, said, "You can't help it if you live in a place where there's lots of shooting. You can just get caught in the middle.

"I've had guns pulled on me by guys who think I'm an undercover cop, and I get picked up by police all the time because I look like every suspect in town," said Prater as he waited for a bus on Wheeler Road SE, near the Maryland line.

"Now everybody is into the 9mm and the Uzi," he said. "It's one thing to see somebody pull out a handgun, but these things are not to be believed. We used guns like that in the Marine Corps. The police don't stand a chance now.

"It used to be $30 and $40 guns, but now it's the expensive ones," Prater said. "I've heard people tell their partners they want to use their gun and the partner charges them. You know, if someone is paying to rent a gun they're getting ready to use it."

Cassandra Williams has seen the youths in her Capitol Heights community and in Eastgate, a neighborhood off Benning Road SE, show off their guns, brag about who has the best and whose gun has the most firepower.

"I know a whole lot of people who carry guns," the 15-year-old said. "They talk about them. They play with them. They show them to see who has the best and they shoot them in the air. I've seen .45 magnums and little guns.

"It scares me when I see them," she said. "I just go the other way. I don't think anybody should have guns. They call themselves protecting themselves, but they just shoot people because they owe them money."

At the 7-Eleven on Wheeler Road, across the street from where Williams and Prater stood, a booklet called "The Want Ad Weekly" was on sale for $1. Prater pointed out that youths bought the book to check out ads on guns for sale. In the latest edition, ads included a "fully automatic 9mm for $600" and a 357 magnum for $350.

The store is just a couple of blocks from the Greater Southeast Community Hospital.

The hospital is in the 7th Police District, one of the busiest drug markets and an area leading the city in the number of homicides this year. At Greater Southeast, medical technicians have grown weary of the steady stream of young males brought into their emergency room nightly, their bodies wounded by bullets.

"Not only has there been an increase in the number of shootings I'm seeing, but it looks like people are being shot with more powerful weapons, large-caliber bullets, automatic weapons," said Dr. Michael Lippe, an attending physician in the hospital's emergency department.

"When I first started, most gunshot wounds were from .22-caliber, small handguns," said Lippe, who has worked in the emergency room for four years.

"Now we're seeing .38 and .45 calibers and some larger guns. We're also beginning to see injuries from automatic weapons . . . a person comes in with 16 bullet wounds. Of course, those patients are usually dead.

"The thing that upsets me is you can almost predict the deaths," said Lippe. "We see young men come in with a minor gunshot wound, and you can see they are on drugs.

"They're wearing gold chains and have several thousand dollars in their pockets. They're living a fast life and you know it's a matter of time before they come back shot worse -- or dead.

"It's a real waste of young life."

From Jan. 1 through Nov. 30, l987: 2,526 weapons were confiscated, including 696 seized from July through October in Operation Clean Sweep.

During the same 11-month period in l986, 1,961 weapons were confiscated.

Of the 696 weapons confiscated from July through October in Operation Clean Sweep this year, traces have been completed on 172: At least 5 were purchased at Virginia gun stores; 17 were purchased at Maryland gun stores,and 52 were too old to trace.