The effectiveness of such programs has been debated, but they very well might save lives, supporters said, and at worst can't do any harm.
"By taking these measures today, we are certainly preventing senseless tragedies," King County Executive Dow Constantine told a news conference at Mount Zion Baptist Church in Seattle. "How many? That will never be known."
The program was announced on the two-year anniversary of the Tucson, Ariz., shooting that killed six people and left then-U.S. Rep. Gabrielle Giffords critically injured. It also came a month after a gunman in Newtown, Conn., opened fire in an elementary school, killing 20 children and six adults.
Amazon.com, which has been expanding its headquarters in Seattle, kicked in $30,000 in Amazon gift cards - $100 for each handgun, rifle or shotgun turned in, and $200 for each gun classified as an assault weapon under state law. In an emailed statement, the company said only that it thanked Seattle Mike McGinn for the invitation to participate and that it was happy to do so.
The Seattle Police Foundation donated $25,000, Seattle-based search engine optimization software company SEOmoz gave $10,000 and PEMCO insurance committed $5,000. That money will be used for gift cards from other retail or grocery stores.
The first buyback is scheduled for Jan. 26 under Interstate 5 between Cherry and James streets downtown. Additional dates are expected to be announced later. Unless they have historical value, the guns will be melted down and recycled.
Participants need not worry about being arrested, officials said. Police won't take photos or record license plates. They will run serial numbers to see if the weapons have been stolen; if so, ballistics tests will be performed and officers will try to return the weapons to their legal owners. Otherwise, no ballistics tests will be conducted, said Seattle Police Deputy Chief Nick Metz.
"This isn't a trick, and this isn't a sting. Whether you're turning an anti-tank missile launcher you 'found' in your basement, or your Gammie's old .45, the buyback is anonymous with no questions asked," the police department said in a statement.
Seattle had 27 homicides last year, relatively low for a city its size - but 23 of them were in the first five months, including the fatal shooting of four people at Cafe Racer and another in a carjacking by Ian Stawicki on May 30.
Seattle last tried a gun buyback in 1992, when 1,172 firearms were relinquished, said former Mayor Norm Rice, who is joining former mayors Greg Nickels, Charles Royer and Wes Uhlman as co-chairmen of the new Gun Safety Initiative.
A similar gun-buyback program in Los Angeles last month netted more than 2,000 weapons, including 901 handguns and two rocket launchers.
McGinn and Constantine said the buyback program isn't designed as a panacea but as one tool to reduce gun violence. If a single shooting never materializes because of it, the effort will have been worth it, they said.
But Dave Workman, senior editor at The Gun Mag, a publication of the Second Amendment Foundation, described such programs as political theater that doesn't make anyone safer.
He pointed to a 2004 study by the National Research Council. It questioned the effectiveness of such programs, saying the weapons typically turned in are those least likely to be used in criminal activities, guns are so readily available that the programs have little practical effect, and with tens of millions of handguns in circulation in the U.S., the odds any particular weapon will be used in a crime are minuscule.
"We've had a history of these gun buybacks around the country, and they really haven't done anything," Workman said.
Metz argued that getting unwanted guns out of the community is a laudable goal: It means they won't be involved in an accidental shooting or stolen and used in a crime.