RICHMOND, JAN. 11 -- The execution-style shooting death of a security guard in a McDonald's parking lot here as hundreds of teenagers looked on is fueling the debate over gun control that will take place as Virginia legislators return to the city for their 1993 session this week.

The shooting, Richmond's first homicide of the year, spurred calls for quick passage of legislation backed by Gov. L. Douglas Wilder that would limit gun purchases in Virginia to one a month per person.

"The governor's proposal is a good first step, but it's not enough," said Isham "Ike" Draughn, of Arlington, father of the 24-year-old victim. "There are too many guns out there. I'd like to see them all melted down."

Wilder's press secretary, Glenn Davidson, said the governor believes that the slaying "demonstrates that the easy availability of guns inevitably leads to these kinds of senseless acts."

None of the witnesses to the killing of Isham Douglas Draughn II would cooperate with police at the scene. Angered by the "conspiracy of silence," as Police Chief Marty Tapscott called it, City Manager Robert E. Bobb has called for an ordinance that would allow Richmond police to round up homicide witnesses and hold them for as long as 60 hours as a way of getting information.

Bobb said he understands that his proposal may be unconstitutional and said he made it "out of absolute, total frustration." He said Richmond and Norfolk officials failed to persuade the 1992 legislature to limit gun purchases in a bill similar to Wilder's.

"I'm so glad the governor is taking the lead," Bobb said. "In politics, timing is everything."

Tapscott, a former deputy police chief in the District, said Wilder's legislation likely would not have saved Draughn because guns are available on the black market and through burglaries.

"I'm not naive enough to think that it would stop this kind of thing," Tapscott said. "I know criminals will get their hands on guns . . . . But we need every tool we can get."

The shooting occurred about 2:20 a.m. Saturday as Draughn was attempting to put handcuffs on someone who had been involved in a disturbance inside the all-night restaurant.

Police said Draughn was shot in the back of the head. The shooting and the arrival of a dozen patrol cars, which earlier had been dispatched to the area because of disturbances at a nearby nightclub, set off a melee, as young people ran to their cars or broke down a metal fence that separates the restaurant from an adjoining gas station.

Not everyone fled, however. A report in the Richmond Times-Dispatch said that a number of youths hung around and that some of them were laughing as police investigated.

"It was mayhem when we got here," Lt. John Carlson told the newspaper. "Somebody saw it. Somebody knows who did it."

Ike Draughn said gun-control opponents might change their minds if their children were the victims of such killings.

"When people {outside poor neighborhoods} start getting killed, then they'll get an idea," he said.

Mayor Walter Kenney said Bobb's proposal to detain witnesses is not worth serious consideration. But he also expressed outrage at the city's reputation for violence -- the 120 homicides recorded last year in a city of 220,000 ranked the Virginia capital third per capita among the country's large cities, behind Washington and Detroit.

Kent Willis, executive director of the Virginia chapter of the American Civil Liberties Union, said Bobb's frustration "is understandable, but it's outright stomping on constitutional rights. The city manager should do everything possible to get people to step forward, but he can't compel witnesses in that fashion."

Bobb said he will ask the city attorney to determine if "there isn't some small crack" in the Constitution that would "legally allow the police department to bring everyone into their custody until they effect an arrest."

Jaie Brown, a spokesman for McDonald's, said Draughn was one of three guards on duty at the restaurant Friday night. She said they were armed.

Draughn had worked for the guard service hired by McDonald's, First Search Corp., for three years, according to his father.

"He loved it. It was his life," Ike Draughn said. "He talked to me and his mother about the danger, but he said, 'That's the way the world is. You can get killed walking down the street or in a carjacking.' "