paulallen2First Steve Ballmer, Bill Gates, and Nick Hanauer showed their support for a new law that would require stricter background checks for gun sales in Washington. Now Paul Allen is joining the charge.

The Microsoft co-founder has pitched in $500,000 to the Washington Alliance for Gun Responsibility, a coalition that wants to require background checks for Washington residents who buy firearms at gun shows and online.

Ballmer and his wife Connie have poured in nearly $600,000 in support of the initiative, while Bill and Melinda Gates donated $50,000 last year. Hanauer, a prominent Seattle venture capitalist, has contributed nearly $400,000.

The group is responsible for nearly one-third of the $3.5 million given to the Washington Alliance for Gun Responsibility.

Initiative 594, which will be on the November ballot, would close what the alliance calls a “loophole.”

“Law enforcement agencies and public safety officials agree that this loophole promotes illegal gun trafficking and enables individuals with criminal intent to purchase firearms,” the alliance notes. “This initiative will simply ensure that a background check is conducted for every gun purchase.”

I-594 would include some exemptions, including gifts within a family, antique firearms, and temporary transfers to prevent death or injury.

While many from law enforcement agencies support the initiative, there are some organizations like the Washington Council of Police and Sheriffs who oppose I-594 and instead support Initiative-591, a competing measure that would prevent Washington from enacting background check requirements that are not required by federal law.

An April poll found 72 percent of Washington voters in support of I-594, but also 55 percent in support of I-591.

This is one of Allen’s largest initiative donations. He put more than $2.5 million to a public school campaign in 2000 and gave $500,000 to a group called “CIT For More Important Things” in 1997.

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