The group Washington Alliance for Gun Responsibility will need to collect nearly 250,000 valid signatures, with state officials recommending the submission of more than 300,000 to account for duplicates and invalid signatures. Organizers are still finalizing language for the initiative and will begin gathering signatures in the summer months.
Snohomish County Sheriff John Lovick was among those who are supporting the campaign.
"For law enforcement, criminal background checks are essential in protecting lives and property," Lovick said.
Gun buyers must currently undergo a background check when they purchase a weapon from a federally licensed firearms dealer. Lawmakers in Olympia had proposed expanding that to cover private transactions, fearing that criminals or the mentally ill were acquiring guns without sufficient checks.
That legislative effort fell short in recent weeks.
Advocates believe the polls show the public is sufficiently on the side of expanding background checks. An independent Elway Poll conducted two months ago found that 79 percent of registered voters in Washington state supported background checks on all gun sales, including private transactions.
However, gun control supporters also believed polls were on their side before 70 percent of Washington state voters rejected a 1997 initiative campaign that would have required handgun owners to pass a safety course.
The new initiative effort will likely be costly. Christian Sinderman, a political consultant working with the gun control group, expected the campaign could cost somewhere between $3 million and $10 million - or more. The group will have costs for collecting signatures, then reaching out to voters and potentially competing with an opposition campaign from pro-gun groups.
Dave Workman, a spokesman with the Bellevue-based Second Amendment Foundation, said he couldn't really comment on the proposed initiative since the details of the measure hadn't been drafted.
"We're a little skeptical about it," Workman said. "The devil is always in the details with these things."