(NewsNation) — We are still learning details of how police responded to the school shooting in Uvalde, Texas, but the grim reality of numerous prior school and mass shootings have given law enforcement evidence of how to approach these situations.

“If you’re the first officer on the scene, you’re trained to go into the gunfire,” said Dr. Frank Straub, who serves as the director of the Center for Targeted Violence Prevention at the National Policing Institute. “That’s the reality — that if you get to a scene, you’re the first officer on location, you report on the radio what’s going on, you call for backup, but you go in and try to find the shooter or shooters and neutralize.”

Straub spent three decades in law enforcement and has closely studied the police response to mass shootings and active shooter situations.

Dr. Kathryn H. Floyd, the director of the Whole of Government Center of Excellence at William & Mary and a longtime expert on mass violence, concurred with Straub’s opinion.

“Most of today’s shooters are not interested in being taken alive. They seek fame and notoriety for their unconscionable decisions,” Floyd said.

Straub explained the thinking about how police should respond changed after the 1999 Columbine school shooting.

“The model was that you would get there and you would contain the scene until the SWAT team showed up and then they would be the ones that would make entry because they had specialized training and they had specialized equipment,” Straub said.

But the Columbine shooting showed that shooters can cause a lot of harm while police wait for specialized units to arrive. That’s when police started to settle on a new response, which could serve as a more effective solution to these situations.

“And so it was after that that we started training officers to go to the gunshots. That’s the phrase that’s used, right,” Straub said. “If you arrive on scene, and you hear gunshots, you go to the gunshots. To the point where, in training exercises, you don’t stop to help victims. You go to the shooter.”

Straub cited a number of examples where police responded rapidly to mass shooters, exemplifying an effective response that can serve as a model for police. In the 2015 San Bernardino mass shooting, the first police officer was on the scene within three and half minutes after hearing the initial dispatch. That officer worked with three other officers who also responded to the call to immediately enter the scene of the shooting.

The 2016 Pulse nightclub attack represented another situation where an off-duty police officer who was working detail at the club immediately engaged the shooter; within a minute of the call alerting them to shots fired, additional Orlando Police Department officers responded and the shooter was driven to the rear of the club, where he barricaded himself in a bathroom.

“These shooters know they have somewhere in the realm of two to five minutes, hopefully less, before law enforcement arrives,” Floyd said. “The longer that takes and the more time that passes before trained law enforcement engages, the more people are likely going to die.”

Of course, not every officer who is closest to a scene will always successfully put an end to the shooting, particularly when shooters carry advanced weaponry and wear protective gear.

“Unfortunately, we’re seeing (the shooters) armed with very sophisticated weapons systems that the officers don’t necessarily have to their advantage,” Staub said. “In Buffalo, that individual, it’s been confirmed, had a ballistic vest on, right, that was capable of stopping rounds.”

Straub concluded that there were three things police officers need to respond effectively to mass shootings: proper training on how to respond, adequate equipment — like ballistic vests or weapons that can go toe to toe with AR15s — and medical gear that can allow them to keep themselves alive if they’re injured.

Floyd added that it’s also necessary to offer police departments training on what to do in the aftermath, emphasizing the importance of offering mental health support to responders after incidents.

“Police chiefs should anticipate that trauma or vicarious trauma may appear in the ranks during the weeks and months that follow,” she said.