The return count was nearly evenly split between pistols and rifles, and among the weapons turned in were three "street sweepers" -- shotguns that include a high capacity magazine capable of holding twelve 12-gauge shotgun shells -- and a military surface-to-air missile launcher.
"There was clearly a lot of pent up demand for a gun buyback," said Seattle Mayor Mike McGinn. "I'm pleased that so many people were able to safely dispose of unwanted guns."
The massive turnout clogged traffic on Sixth Avenue and on an I-5 off-ramp leading to the buy-back area, located in a parking lot underneath the freeway between James and Cherry streets.
Scalpers offering cash for guns held up signs on surrounding streets, trying to tempt gun owners before they reached the official drop-off point.
"It was absolutely crazy what we saw out there," McGinn said.
A man standing outside the event bought the military weapon for $100 from another person there, according to Detective Mark Jamieson. Police witnessed the private exchange and then spoke to the buyer, who was cooperative. Officers then inspected the launcher and determined that it was unarmed. However, police confiscated the weapon because it is considered a controlled military item, Jamieson said. The man was offered a $100 gift card and the launcher was set to be turned over to military officials.
Officers saw other guns changing private hands without knowing whether the person buying the gun had the legal right to buy it, and those transactions are occurring all the time, McGinn said.
He added that the private sales of the missile launch tube and other weapons illustrate the need for comprehensive background checks as proposed by President Barack Obama, as well as other regulations at the state level.
While there were private gun buyers at the periphery of Saturday's event, Metz said a large majority of people chose to wait in line and get less money because they wanted to make sure they got the weapons off the streets.
"These are very dangerous weapons," Metz said. "They may not have looked very pretty, but (they're) definitely operable."
The buy-back originally was scheduled to continue through 3 p.m. But at 11:45 a.m., police were forced to turn away anyone who wasn't already in line as they started running low on gift cards. In all, $68,000 in gift cards were handed out on Saturday.
Seattle police had about $80,000 in gift cards on hand through several donors, but opted to keep some in reserve for a future buyback date. They are soliciting more donations.
"The turnout shows the demand is there, and I thank all those who donated funds to provide the financial incentive," said King County Executive Dow Constantine.
Meanwhile, police said citizens who wanted to turn in guns could do so at any time outside a buyback program, though they wouldn't be compensated for it.
Four of the guns turned in were confirmed to have been stolen. Police said they will contact the owners of the gun and ask if they want it returned or destroyed.