But the program was so successful that on the third day, some of those lined up to exchange their firearms this week had to be turned away because the program temporarily ran out of money.
Across the country, police and community groups running similar programs have attracted thousands of people ready to turn in guns for rewards. In some cases, the response has been so overwhelming that cash-strapped cities have cut back their efforts.
In other places, officials are making payments with gift certificates, sneakers or even sewing machines to make sure that people giving up their guns won't turn around and buy new ones.
The right incentives have persuaded some people to get rid of weapons they no longer need or feel comfortable keeping around the house.
D.J. Scott used to hide his .44 caliber gun in the basement. But Scott said reports of youths accidentally shooting guns made him wary of keeping the weapon in a house with five children.
"If they look around long enough, they'll find it," said Scott, toting a gun inside a paper bag at one of Washington's police stations Friday. The city's program, after temporarily running short of cash, continued the collection Friday, after already taking in more than 400 guns.
"For $100 for an old gun, I'll take it," said Amelia Harris of Cheverly, Md., who was turning in a tarnished gun that had belonged to her grandmother.
Even the thousands of weapons turned in through such programs over the past few years barely makes a dent in the number of firearms in circulation across America, estimated at 220 million to 250 million by the Bureau of Alcohol, Tobacco and Firearms. Those figures do not account for firearms destroyed or rendered unfit for use, souvenirs brought back from overseas battles, guns smuggled into or out of the country or guns manufactured illegally.
ATF does not keep track of how many guns are collected through the firearms swaps.
A key draw of buyback programs is the "no questions asked" policy that affords protection to those who turn in guns.
"If we start taking names, we would only get legally owned guns," said Lt. Edward Zunino of Kennett Square, Pa., where a gun buyback program in place since May has drawn in 25 rifles and 30 handguns.
The monetary rewards, meanwhile, have lured an avalanche of participants. In Connecticut, a 1994 statewide gun swap drew so many weapons the program quickly wound up owing $400,000 more than it had to give away. The program that offered a sliding scale of paybacks up to $500 in store vouchers for working assault-style firearms had been expected to draw 1,000 weapons over the course of four weeks. Instead, it attracted 4,000 guns in just four days.
Budget constraints prevented the Salt Lake City police depatment from offering money, so they had collected only a handful of guns during a 10-day program that ended Friday. A city buyback program several years ago drew about 1,000 guns.
In June, Brooklyn District Attorney Charles Hynes initiated a guns-for-cash program dubbed "Turn it in for a Benjamin," referring to Benjamin Franklin, whose portrait is on $100 bills. After collecting more than 650 guns, the program spread citywide.
But some groups have opted not to use cash, including Operation Hope, a nonprofit organization in New Orleans. It considered paying $50 to $100 per gun, but decided against it, concerned that criminals might use the money to buy more guns or purchase illegal drugs.
"We wanted to make sure that the money was funneled into things that were healthy or humanistic," said John Royes, the group's president. Instead, sewing machines or grocery store gift certificates worth $50 or more were given in exchange for guns.
Some police departments are asking police ballistics laboratories to determine if turned-in firearms might be linked to any criminal investigations, but are not using them as trial evidence.