Lt. Mike Madden of the San Bernardino police was on his way to lunch when a dispatcher sent out word of an active shooter at the Inland Regional Center.
Madden is a police administrator, and dispatch is one function he oversees. He could tell from the dispatcher's voice that "this was actually happening, a real event ... We have an active shooter and we have an active shooter going on in our city."
He headed for the scene and was one of the first to arrive; as a few others got there, his priority was to put together a team to enter the building.
"We had every belief at that time," he said, "that people were still being shot."
He and his team entered the conference room where the shooting had begun and found blaring fire alarms and victims either dead or moaning in pain.
He was shocked, despite active-shooter training during his 24 years on the force.
"They just try to throw everything at you to prepare you for dealing with that," he said late Thursday. "What you're seeing what you're hearing, what you're smelling — and it was all of that and more. It was unspeakable, the carnage that we were seeing."
Witnesses were telling officers there were as many as three gunmen, so even after police started hearing that two people had driven away, they believed there could have been another killer roaming free.
"We went further into the building — and that was a difficult choice to have to make as well, passing people that we knew were injured and needing assistance," he said. "But our goal at that time had to be to locate the shooters and deal with them."
As the officers cleared the building, they sent people out. One group of about fifty resisted leaving, and Madden worried that there was a gunman he couldn't see who was holding them hostage, highlighting the stress everyone in the situation was under.
As help flooded in, Madden was able to return to his role as supervisor.
Late Thursday, as he told his story to reporters at a news conference, Madden talked about the beating that the reputations of police have taken — a justified one, in some cases, he said.
"It takes a toll on all cops, because it's hard being labeled ... as being rogue," he said. "I guarantee you that no cop comes into this job with the mindset that, 'great, now I have the ultimate power to be corrupt and to violate people's rights.' There are cops who go astray, but overwhelmingly the vast majority of officers ... go out and they do the job to protect the public."
The longtime San Bernardino resident said the public has been letting him know since that crime that "there is support for law enforcement."