By Sari Horwitz and Martin Weil
Washington Post Staff Writers
Sunday, July 16, 2006; C10

A 23-year-old Prince George's County man was stabbed to death early yesterday in the Adams Morgan section of the District after an argument that may have begun over rap singing, D.C. police said.

The killing of David C. Murphy was the city's 15th in the first 15 days of July. The outbreak of violence prompted Chief Charles H. Ramsey to declare a crime emergency, which has drawn national attention.

The killing was the latest in a spate of violent assaults that have alarmed police and residents of Adams Morgan.

Johnisha Knight, 26, of the 400 block of 37th Street SE was arrested shortly after the stabbing and charged with felony murder, said Sgt. Joe Gentile, a D.C. police spokesman. He said she was arrested in a car on Interstate 295.

In an interview last night, the victim's mother called Murphy a gentle soul who was loved by all and was a doting and dedicated father to his 1-year-old son.

A maintenance man in Virginia, "he worked and did for his son," Lutricia Murphy said. "I don't think you could find a person who could say a harsh word about David."

According to initial accounts of the incident, a rap singing competition was being held. Officials said it may have been at Blue Fin, a bar and restaurant with a downstairs lounge, on 18th Street near Kalorama Road. However, the victim's mother named another establishment, nearby.

About 3 a.m., after closing time, officials said, an argument began. According to two accounts, it may have been about singing abilities. Police said groups may have been drawn in.

At some point, according to a police source, someone in one of the groups may have struck someone in the other.

At 3:20 a.m. on a playground in the 2200 block of Champlain Street NW, about a block from the bar, Murphy was stabbed, Gentile said. Murphy lived in the 6900 block of G Street, about a mile east of the D.C.-Prince George's line.

Murphy's mother said she understood that her son had been at a club in Adams Morgan participating in a "freestyling" competition, in which one person raps and then another.

She said she was told that a competitor became jealous "and took it to the next level."

She said a fight began and her son broke it off to go to his car when an assailant, who had driven away, returned, and he was stabbed nine times.

"My son's not here," she said. "I have to talk to a tombstone."

In commenting on yesterday's homicide, Ramsey expressed frustration over the seeming inconsequentiality of disputes that have led to many killings.

"It's just another example of people killing one another over trivial things," he said.

D.C. Council member Jim Graham (D-Ward 1) said that if a woman had stabbed the victim it would represent "a new crescendo of violence."

"I was told that the girl who was arrested took offense at the way some of the people in one group were singing," Graham said.

Staff writer Clarence Williams contributed to this report.