Slain Boulder Police Officer Eric Talley's sister said she had a sense of what had gone through her brother’s mind Monday as he rushed toward the sound of gunfire.

“I honestly know my brother, when he heard there was a shooting in a supermarket, I know his first thought was, ‘There are kids in there,’ ” Kristin Brooks said. “He loved his kids. His family shopped at King Soopers.”

“I know Eric would have wanted to save every single one of those lives. I know why he flew in there first, because he was thinking, there are families in that store,” Brooks told the Washington Post .

Talley was among the first responders to run into the supermarket on Monday and was fatally shot along with nine others. The oldest victim was 65 and the youngest 20.

More than a decade before the shooting, Eric Talley had a stable job in information technology that provided for his kids and his wife, who educated their children in their Colorado home.

But in 2010, after one of his closest friends died in a DUI crash, he quit, left behind his master’s degree and enrolled in the police academy at age 40, according to his friends and family.