(KRON) — When looking at police response to mass shootings, the protocol up to and during 1999’s Columbine massacre was quite different.

The officers did engage the subjects in the parking lot. But then they followed what the standard protocol was when officers were outgunned, they waited for tactical teams to respond.

“The officers did engage the subjects in the parking lot, but then they followed what the standard protocol was,” said security consultant Brian Higgins. “When officers are outgunned, they waited for tactical teams to respond.

Higgins is a lecturer at the John Jay College of Criminal Justice and a retired Bergen County Police Chief and SWAT team member.

He says after Columbine, the protocol changed.

“Waiting for tactical team is not the answer, Higgins said. “Officers who respond have to go in immediately so long as the shooting is occurring.”

Initial reports suggest police in Uvalde, Texas initially followed protocol by engaging the shooter 4 minutes after he entered Robb Elementary School but then were driven back by gunfire.

Then an hour passed before a tactical team reentered the school and took out the shooter.

“What we need to know is did the shooter stop shooting number one? And were their victims in this room who had not been wounded yet?” Higgins said.

He says if that was the case, there can be an argument made for waiting to reenter the classroom.

“If there are victims who are not injured, still in the room with this subject. If the officers enter and they’re not prepared, they don’t have the equipment and the tools to go in and engage the subject. Then they may create more injuries and more death,” Higgins said. “And they don’t want that. So there’s this balancing act. And we’ll have to we’ll have to get more information to see it was it a balancing act and what were they what were the tactics at the time.”