Federal authorities said yesterday they have dismantled one of the most violent drug gangs ever to operate in the District, charging the alleged ringleader with carrying out or ordering the slayings of 15 people, including one man they said was shot by mistake.

Accused drug kingpin Kevin Gray faces what prosecutors said is a record number of murder charges for a single defendant in the District. When he didn't pull the trigger himself, prosecutors said, Gray arranged for hit men to be rewarded with drugs and cash.

For 12 years, Gray's nameless group dominated the crack cocaine and heroin trade in many D.C. neighborhoods, prosecutors said. Members allegedly gunned down rivals and people they thought might testify against them, catching victims by surprise at a gas station, a beauty salon and on street corners, sometimes in broad daylight.

Gray, 28, and another reputed leader, Rodney L. Moore, are in custody, named with 11 other men in a 76-count federal indictment made public yesterday. Prosecutors said they may seek the death penalty against Gray and Moore, both of Southeast Washington.

Prosecutors said Gray had no lawful employment. He has had previous brushes with the law, including convictions for a weapons offense and assault.

At a time when D.C. police are struggling to solve old homicides and keep pace with new cases, officials said their investigation illustrated that much of the bloodshed in the District can be tied to gang-related warfare. All told, the gang was accused of killing 16 people in the District and Virginia and attempting to kill 12 others. Except for one killing, Gray was in the thick of the planning, authorities said.

"A relatively small number of people is responsible for the majority of violence in the District," said D.C. Police Chief Charles H. Ramsey, who joined U.S. Attorney Wilma A. Lewis and FBI officials at a news conference to announce the indictments yesterday.

"As this indictment indicates," Lewis said, "we will use all available and legitimate means to investigate and prosecute individuals who engage in this sort of ruthless and violent behavior. Our city has had more than it should ever have to tolerate."

Authorities said that Gray was the gunman in five slayings and that he arranged for 10 other people to be killed. Even after his arrest on drug-related charges in October, Gray worked from his jail cell to find someone to kill potential witnesses, authorities said. At the same time, he tried to make arrangements to sell drugs he had stashed at various locations in the District, investigators alleged.

Moore, 34, is accused of helping to orchestrate six killings. He allegedly has ties to notorious drug dealer Rayful Edmond III, who is serving a life prison sentence for leading a multimillion-dollar drug ring in the 1980s. According to court papers, Moore visited Edmond in 1992 at a federal penitentiary in Pennsylvania in an attempt to arrange a cocaine deal with one of Edmond's old contacts.

Gray also has ties to another well-known D.C. drug defendant. He is the nephew of Linwood "Big Boy" Gray, who was acquitted in 1979 of charges that he directed a $30 million international heroin-smuggling ring. Linwood Gray was convicted of tax evasion.

Attorneys for Kevin Gray and Moore did not return calls seeking comment.

According to the indictment, Gray and Moore chose murder as a way of cementing their hold on the local drug market. The first killing took place in October 1990, when Gray allegedly shot Anthony Lee Dent, 24, over a drug debt in Southeast Washington.

The group allegedly sold hundreds of thousands of dollars' worth of cocaine, heroin and marijuana over the years on many city streets, including the 2800 block of Robinson Place SE; the 1500 block of Alabama Avenue SE; the 3100 block of 15th Place SE; the 4300 block of Halley Terrace SE; and stretches of Sixth Street NE and H Street NE.

The gang's enforcers routinely tailed their targets, the indictment said.

The charging document, for example, describes the May 1996 search for Ricardo E. Bailey, who Gray and others believed was cooperating with police. Bailey was spotted by a gang member at a gas station in the 3200 block of Pennsylvania Avenue SE, the indictment said. Gray allegedly raced to the scene and killed Bailey, 21.

Two years later, the group allegedly staged a similar search for Roy Cobb, 34, described in the indictment as a rival. They gathered near Ludlow-Taylor Elementary School in Northeast Washington in hopes of finding him. Cobb didn't turn up there but was spotted later at a beauty salon in Northwest Washington, where a hit man, allegedly using a .40-caliber pistol from Gray, shot Cobb in the head. The killer was rewarded with crack cocaine, the indictment said.

Like Cobb, most of the shooting victims were rivals, prosecutors said. Three men were killed because they were viewed as potential witnesses, they said. In later years, Gray loaned his enforcers to carry out three killings for others, they said. That led to the March 1999 killing of Jaime Pereira, the man who was shot by mistake, prosecutors said.

Pereira, 51, a Guatemalan immigrant, worked at an auto body shop in Colonial Beach, Va. His boss was the intended target, prosecutors said. When the hit man later discovered that he had shot the wrong man, he allegedly returned, only to shoot at another wrong man.

The Safe Streets Task Force, which comprised D.C. police detectives and FBI agents, gathered evidence through surveillance and interviews of suspected gang members and associates that led to the indictments in U.S. District Court. According to court papers, authorities obtained court-ordered wiretaps on Gray's cellular telephone, recording roughly 1,000 calls. They also secured the cooperation of at least 25 witnesses.

The indictment includes charges of conspiracy, racketeering, murder and drug trafficking. The case was assigned to U.S. District Judge Royce C. Lamberth.

Gray and Moore have been in custody since October, when they were named in a federal drug-trafficking indictment. Besides Gray and Moore, those charged yesterday are Maurice Andrews, 29; Bryan Bostick, 30; Frank Howard, 30; Roy Johnson, 32; Derrick Moore, 32, who is Rodney Moore's brother; Wilford Oliver, 52; John Raynor, 26; Dennis Robinson, 25; Kenneth Simmons, 30; Omar Wazir, 30, and Jermaine N. Vick, 27.

Metro staff researcher Bobbye Pratt contributed to this report.