Just a few months ago, I was at work as an attorney and the proud father to Christopher Ross Michaels-Martinez, my only son. But after Chris was killed in the mass shooting in Santa Barbara on May 23, 2014, my work suddenly seemed unimportant. I resolved to honor Chris’s life and the lives of so many others who have been killed by preventable gun violence by taking action to address the heartbreaking cycle of gun violence in our communities—and to urge others to join me in the fight.

Washington State is on the brink of taking that kind of meaningful action. I was in Washington recently, where I had the chance to share with voters why I strongly support Initiative 594, the state ballot initiative that would close the loophole in Washington’s background check system.

But I was also in Washington as a grieving dad with a story I wish I didn't have to tell. I was there to honor my son's memory and help draw attention to the importance of keeping guns out of the hands of dangerous people. Closing the background check loophole by passing 594 is one very effective way of doing that.

After Chris was killed, my statements and public display of emotion attracted the attention of the press. My first reaction to that attention was to withdraw. I did not want to share my son with strangers. But then I realized that I needed to share my grief and tell people how much Chris meant to me, so that Chris would not be just another number. Though consumed with grief, I had a moment of moral clarity. I don’t want other parents to go through what I have—to have a child killed by senseless gun violence. From that moment on, I resolved to work toward keeping communities, schools and families safer from gun violence.

I am not so naive as to believe that passing Initiative 594 will end all gun violence in Washington, but we do know this: Background checks reduce crime and save lives.

In states with background checks on all gun sales, 38 percent fewer women are killed by an intimate partner and 39 percent fewer law enforcement officers are killed with handguns. What’s more, new research tells us that existing federal background checks in Washington have blocked over 40,000 dangerous people from buying guns since 1998, including over 6,000 domestic abusers.

These numbers represent real convicted felons and domestic abusers who might otherwise have put Washington lives in danger. In short, background checks are already working. But we can do more.

Currently, all gun purchases at the nearly 1,100 licensed dealers in Washington are subject to background checks. But under current law, background checks are not required when buying from unlicensed sellers—such as at gun shows, online on websites like Armslist, or even between strangers in parking lots. This means that even when convicted felons, domestic abusers, and the seriously mentally ill are rejected at Cabela's or another licensed dealer, they can easily go out and purchase a gun through an unlicensed seller, no questions asked.

Initiative 594 would close this loophole and require that everyone—no matter who they are and from whom they buy a gun—passes the same background check that has been in place and working well for hunters and gun owners for decades.

Last month, I met hundreds of Washingtonians who are working to pass this common-sense measure. Too many families have had to bear the pain of losing a son or daughter to gun violence—and with Initiative 594, we have a real chance to stand up and pass a measure that will keep our communities safer from these senseless tragedies. Initiative 594 won’t just honor the legacy of our lost loved ones—it will help give us a safer future. I urge you to join Washingtonians who are already taking action— including law enforcement officers, teachers and gun-owners—and vote YES on 594.