Former Aurora Police Department chief Dan Oates found himself filled with the same feeling of dread Monday morning as he did in the early hours of July 20, 2012. 

Oates was in charge in 2012 when a gunman wearing body armor, using tear gas, armed to the teeth, opened fire on a sold-out showing of The Dark Knight Rises in Aurora, Colo. Twelve people were killed and 70 others were injured. The shooting rocked the country. The gunman was sentenced to life without parole. 

Now the chief of the Miami Beach Police Department, Oates spoke with The Hollywood Reporter after the deadliest mass shooting in the country's history, which took place Sunday night when at least 59 people were killed and 527 others injured when a gunman opened fire on concert goers in Las Vegas. 

"This is a new order of magnitude: automatic weapons," Oates told THR. "It is as if each new person wants to be bigger and more grandioso than the one before, so it is absolutely perverse." 

Following the Aurora attack, law enforcement officials reexamined their response measures to an active shooter, mass-casualty situation. And now those must change again, Oates said. 

"I guess law enforcement, when there is an aerial opportunity, now has to take those factors into account — what buildings are in line of sight within shooting distance and what security can be done in those buildings prior to a concert," Oates said. "We already do that for high-threat protectees. If the president is going to be in town, you put in special measures for all the buildings that are in the vicinity. So we're going to have to apply that kind of thought to venues like this. It's not something we thought about in the past that we now are going to have to." 

The dead 64-year-old Las Vegas gunman perched himself on the 32nd floor of Mandalay Bay Hotel and Casino and hailed bullets down on an outdoor country music festival.

Oates noted that a major tactic from the theater shooting is now routinely practiced by law enforcement and first responders around the country.

"The profession has learned the lesson of Aurora, which is if you can't get the medics to where the wounded are, evacuate the wounded by any means possible," he told THR.

Victims from the theater shooting were quickly put in police cruisers and other cars and rushed to the hospital — there was no time to wait for ambulances — which also happened Sunday in Las Vegas, according to video from the scene. 

"There is more training than ever on active shooter response, a better response," Oates said. "I think everybody rethought their armor, their weaponry. There are a lot of fire departments around the country who are being issued, if not individually, a stockpile of heavy armor in case they have to go into an [active shooter situation]. We issue tourniquets to police officers now." 

The chief, almost in disbelief, said when he began his career in New York 37 years ago, police didn't even carry shotguns in their cruisers; the idea of an officer needing a high-powered rifle would have been unimaginable. Now, it is common practice.

Oates was "awash" in a feeling of dread and hopelessness when he learned of the Las Vegas shooting and said he even contacted some families of victims from Aurora just to touch base and check on them.

"We have to move on and prevail over evil," he said. "We have to do our best as a society to cope with this."