(NewsNation) — Las Vegas Metro Police began releasing body camera videos of officers responding to a shooting at the University of Nevada, Las Vegas (UNLV), which left three professors dead and a fourth injured.

The chaos that takes place in the videos is “absolutely what you expect to see,” Retired NYPD emergency services unit detective Andy Bershad said during an appearance on “Elizabeth Vargas Reports.”

“I think a lot of times we forget that the responding officers are also humans,” Bershad said. “They’re moving rapidly trying to find a target in a large commercial building. … They’re trying to thin out as much as they can so they can narrow down their search.”

At one point, officers responding to the shooting appear to mistake the gunman for a bystander and urge him to escape the building.

Bershad acknowledged that the gunman “could have easily gotten away,” but ultimately police were “doing their job” by trying to evacuate as many people as possible.

Responding UNLV officers eventually identified, shot and killed the gunman, Anthony “Tony” Polito, 67.

NewsNation affiliate KLAS reporter David Charns contributed to this report.