Andy Parker, welcome to the parents of children killed by guns club: Column You're part of an awful group nobody wants to join. I know, because I am too.

Richard Martinez | USA TODAY

There are no words for how I felt when I watched Andy Parker on TV talking about the murder of his daughter Alison, a promising journalist killed while doing what she loved.

That was me last year. The same TV bookers calling my phone. The same searching questions on live air. The same crushing heartache over having my only child, Christopher Ross Michaels-Martinez, killed by senseless gun violence. He was shot and killed in Isla Vista, California, in a story Americans are painfully familiar with. A disturbed individual got his hands on a gun — despite many troubling red flags in his history — and shot and killed innocent people.

So from one grieving father to another, Andy, I share your grief and mourn your loss. I know what you are feeling. You are not alone. Welcome to the heartbreaking club that no one wants to be a part of.

Andy, I am so deeply sorry about the death of your daughter Alison. From what I've read, she was a caring, ambitious, wonderful young woman. Her death is a devastating tragedy for you and for all of Alison’s family and friends.

After Christopher was killed I made a pledge that “Not One More” son, daughter, father, mother, brother or sister should have to grieve a loved one’s death because of preventable gun violence. I committed my life to sparing other parents the phone call that I got on May 23, 2014. The phone call that you, Andy, received yesterday.

You said yesterday, “mark my words, my mission in life is to do something, whatever it takes, to get gun legislation.” You said “this is Alison’s legacy.” I couldn’t agree more.

In the 15 months since Christopher’s death I have traveled the country with Everytown for Gun Safety to put pressure on lawmakers to finally do something about the 88 Americans killed with guns every day and hundreds more injured. The pundits will tell you that my cause — our cause — is hopeless. They’ll say the gun lobby is too powerful for us to make a difference. They are wrong, and my experience is proof.

I worked with advocates in Washington State last year to pass a ballot initiative that closed the loophole that allowed guns to be sold without background checks on the internet and at gun shows. Our work there will undoubtedly save lives. We are following that same plan now in Maine and Nevada, where voters will be able to vote on similar ballot initiatives in 2016. Oregon closed that same loophole this legislative session too.

My experience is also proof that out of unspeakable tragedy, a community can come together and make meaningful change. In my home state of California, we passed a law last year, which will allow family members and law enforcement to present evidence to a judge that a person is a danger to himself or others and temporarily have law enforcement remove guns from the individual's possession. That law can be a model for other states looking to address gun violence.

And in states across the country we defeated the gun lobby’s dangerous agenda to allow anyone to carry guns anywhere at any time. For example, the NRA unsuccessfully pushed for bills in New Hampshire and 15 other states to repeal the permit requirement for carrying concealed, loaded handguns in public. And they lost fights to pass bills that would force universities to allow guns onto college campuses in Florida, Nevada, Montana, and a dozen other states.

We defeated bills that would have repealed the requirement that all handgun sales require a background check in Colorado, Iowa, and North Carolina. Sixty gun lobby backed-bills were defeated in legislatures around the country so far in 2015. We are taking on the NRA and winning in these states.

Our progress isn’t fast enough. Not for Chris. Not for Alison. We continue to witness too many incidents like this week's, or Charleston, or Chattanooga and Lafayette. And the everyday gun violence that doesn’t get national attention. But we have a movement behind us. We have 90% of Americans behind us, and we will win this fight.

It's too late to save Christopher's life, but with the new California law in place now, we can prevent future shooting where the gunman exhibits clear, dangerous red flags and a judge signs off on removing an individual's guns before they do great damage.

Your words will inspire thousands of people to do “whatever it takes” to make sure that “Not One More” family has to experience the pain that we have endured. It’s painful to welcome another father into this club, but I know that together we can keep up the momentum. Too many have died. We can save lives.

Richard Martinez is a senior outreach associate with Everytown for Gun Safety.