Every time there is a mass shooting in the United States, there is a flurry of concentration on those who died, the alleged or confessed perpetrator, and the sobered, devastated town that will be forever changed.

Then at some point, the press caravan moves on — from Sutherland Springs, from Orlando, from Las Vegas. And within weeks, or sometimes just days, another mass shooting is being reported.

The public attention moves on, but those affected families don't.

More families joined the ranks of the grieving this past week, when five people were killed in Rancho Tehama Reserve, Calif.

"It is a pain that will never go away," Tom Mauser says.

He's been living with it for more than 18 years. His 15-year-old son Daniel was killed at Columbine High School on April 20, 1999.

"My son Daniel was a very gentle, soft-spoken kid," Mauser says. "He was a Boy Scout, piano player, loved to play video games, straight-A student."

Daniel was shy, but faced his fears head-on, his father says.

"He chose to join the debate team at Columbine, where he had to get up in front of other people. So I really admire him for that," Mauser told NPR's Scott Simon on Weekend Edition.

More than a decade later, Jane Dougherty's life would change in the same way.

Dougherty's sister, Mary Sherlach, was the school psychologist at Sandy Hook Elementary School. She was gunned down in the school lobby on the morning of Dec. 14, 2012.

"Mary was my older sister," Dougherty tells NPR. "We called her little mother, because she would take charge of the five of us — even my older brothers. So, she lived her life that way. And she died that way. Taking charge, at Sandy Hook."

For most, seeing the news about another mass shooting is a sobering and sad facet of an otherwise normal day.

But for those who've had loved ones die at the hands of gunmen, it cuts much deeper.

"It rips the scab off, every time," Dougherty says. "There's less and less time to heal between them. And for me, I cannot turn away from the news. I think because I think of every victim as Mary. And I will spend the day watching the horror. And I'm physically ill, I think I end up internalizing everything, and eventually I crash. And it happens over and over and over again on mass shooting days, that I call my lost days."

"It's the same for me," Mauser says. "As soon as I know that something has happened, it's: OK, this is going to be a very different day, this is not going to be a productive day." He thinks of what those parents are going through and the long journey ahead of them.

The two describe a lifetime carrying a burden.

"For me, I feel like it never ends," Dougherty says. "It's an ongoing living situation. Because there's one [shooting] after another. I feel like I have just figured out how to live with it. You have no other choice. It's kind of a weight you kind of drag around in your life."

Mauser feels the same way — a weight he bears, forever. "It is a pain that will never go away. It will ease up. You'll learn to deal with it over time. But yes, that is something you will carry with you for the rest of your life. And it will become, unfortunately, an identifier of your life."

For those families who are preparing for their first holiday season without everyone at the table, they have some advice.

"It does get better, but it's always there," Dougherty says. She says becoming an activist for something she believes in — stronger gun control laws — has been "therapeutic."

Be prepared for insensitive comments, Mauser says. Some people just don't know what to say to you.

And most of all, Mauser says, you have to learn to not feel guilty for going on with your life, when the time comes.

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