District officials more than doubled the funds for a citywide gun buyback program yesterday after area residents turned in 1,164 guns on its first day, greatly surpassing expectations.

Residents -- some bearing bundles of guns in grocery bags and stories of relatives who had died from gun violence -- received $100 in cash for each eligible, operable gun, no questions asked. The police also granted immunity from prosecution for handgun possession.

Yesterday's effort was initially funded by $100,000 seized from drug crimes, but the amount was increased by $25,000 in the afternoon, and by another $100,000 in confiscated funds last night, as people kept coming.

"I just didn't see an end in sight," said Executive Assistant Police Chief Terrance W. Gainer. The buybacks will continue, starting at 3 p.m. today, until the money runs out.

But although people continued to hand in guns at 9:30 p.m., 90 minutes after the effort was scheduled to close for the night, some questioned whether such programs work.

Criminal justice analysts said such buybacks, which have been in vogue since the 1970s, do little to reduce violent crime. "Any public-safety impact that gun buybacks have is probably quite small," said David M. Kennedy, a senior researcher at Harvard University's John F. Kennedy School of Government who has studied gun exchanges in Boston.

D.C. police countered that every gun taken out of a home reduces the risks to residents -- from suicides or homicides -- and to officers on the street.

"I can say with absolute certainty that there's 1,050 guns that were available to be used in crimes at 3 p.m. and are not now available," Gainer said about 7:45 p.m., as still more guns were being turned in. "This isn't the beginning or end of reducing crime. There's a lot of things that need to be done to make this city safer, but I think it's pretty . . . important."

Crowds lined up outside the seven police district headquarters well before the designated 3 p.m. start yesterday. At 7 p.m., having already added $25,000 to the pot, police decided to put up the additional $100,000 after conferring with Mayor Anthony A. Williams (D) and Police Chief Charles H. Ramsey.

Gainer did not rule out adding even more money to the program, but said, "There's a limit to how far we can stretch these funds."

At the 2nd District in Northwest Washington, officials expressed surprise that so many people showed up. Police said someone turned in a $2,800 Luger and didn't even ask for the $100. One man in Upper Northwest brought in five handguns in a Fresh Fields paper shopping bag. He said that his 40-year-old son had been killed in a domestic dispute with a gun.

Northeast resident Joe Walker, 55, said he was turning in a .38-caliber special from his brother, who died in April. "I didn't need the gun. My house had been broken into six years ago, and a handgun I had for personal use was stolen," he said.

Gainer estimated that 20 percent of the guns came from people who live outside the District.

In Operation Gun Tip, the District's first citywide gun buyback program since 1994, police are paying for handguns, sawed-off shotguns, sawed-off rifles and assault rifles. They are not paying for regular shotguns and regular rifles, although those weapons are being accepted.

Gainer described some of the guns received yesterday as "some of the worst of the worst." Buying or selling a handgun has been unlawful in the District since 1976.

The program follows a highly successful exchange earlier this month at the 6th Police District, which covers parts of Northeast and Southeast Washington. That effort netted about 600 weapons.

After running ballistics tests on the guns to determine whether they have been used in crimes, police will melt down the weapons.

From August 1997 to July 1998, the latest period for which data are available, the Bureau of Alcohol, Tobacco and Firearms recorded 3,292 cases in the District in which authorities recovered a firearm. Most of the charges were for owning a handgun illegally.

Only three gun exchanges in the United States -- conducted in Baltimore in 1974, St. Louis in 1991 and Syracuse, N.Y., in 1992 -- managed to take more than 1.5 percent of a city's gun stock off the streets, according to Gary Kleck, a professor of criminology and criminal justice at Florida State University. The size of each city's gun stock is inferred from national data, Kleck said.

Gun amnesty programs also tend to net older guns, although three-quarters of the 250 million guns in this country were made in the past 30 years, Kleck said.

Torin Suber, a police firearms examiner who was at the 7th District in Southeast Washington yesterday afternoon to determine whether the guns being turned in were operable, said most of the weapons were 10 to 15 years old. The weapons included sawed-off shotguns and 9mm semiautomatic pistols, but .22-caliber revolvers were the most common, Suber said.

Jon S. Vernick, associate director of the Johns Hopkins Center for Gun Policy and Research, said gun exchanges may not reduce the overall level of violent crime in a community but they have other positive effects. "Homes with guns in them are about three times more likely to experience a homicide and about five times more likely to experience a suicide than are homes without guns in them," he said.

At the 7th District, Ann Batiste, 58, of Fairlawn, said she was turning in a rifle that had stayed in her closet 11 years. "I just don't want it in my house," she said.

Nearly half of those in line were women.

"A lot of us women, we're getting something out of the house that is dangerous and that we're not supposed to have," said a 43-year-old Anacostia resident who identified herself only as Mrs. Lowery. She turned in a .22-caliber handgun that her father had left her. "And it gives us money. I don't see anybody here who couldn't use $100."

A man who only gave his name as Harvey, a 76-year-old retired electrical engineer from Upper Northwest, came to turn in a .22-caliber pistol he used for target practice. "My wife didn't want it anymore," he said. "We're both in our late seventies."

Asked what he'd do with the money, he said, "I'll give the money to her. She'll run up to Lord & Taylor."