Transcript for Officers' body cams show inside horrific Colorado apartment attack

Yeah. A yeah. News. You come out. Yeah. Yeah arm. Yeah. Heard all the shots. I could see the muzzle flashes. This. This was never like anything I've ever imagined would say probably thirty round magazine. He dumped on us within a couple seconds. I hear it. Zack saved. And shot and bleeding out her or one out of when he medical figured out. Zach is down any heroes no other way about it is the he's the poster child for. You want to hire as a police officer who you want is serving your community. That's O Zack wants.

This transcript has been automatically generated and may not be 100% accurate.