ARVADA, Colo. — Mass shootings are becoming a recurring nightmare for law enforcement in Colorado.

First it was Columbine, then Platte Canyon High School and the Youth with a Mission in Arvada.

Those tragedies were followed by the Aurora theater massacre and finally, the shootings at Planned Parenthood on Colorado Springs on Friday.

Arvada Police Sergeant A.J. DeAndrea has been a part of several of those SWAT responses and has seen the law enforcement response evolve following each of those tragedies.

“We will learn from this incident and unfortunately we know there will be more,” said DeAndrea.  “We learned at Columbine that was not the right formula, the right plan, to be able to step up and save lives.”

On Friday, the first officers on scene didn’t wait for back-up. Unlike Columbine, they immediately engaged the suspect and tried to get into Planned Parenthood.

“When the suspect turns their attention on us, they can’t continue to kill the innocent. We have body armor and weapons,” said DeAndra.

Police also escorted unarmed firefighters into the building while it was occupied by the gunman, instead of waiting for the standoff to end.

“In Colorado that’s the first time we’ve seen that, yeah. Our goal is to save lives and if we’re waiting outside, we can’t save lives,” said DeAndrea.

Technology has also improve the police response.

On Friday, law enforcement monitored the suspect on multiple surveillance cameras while another team studied the layout of Planned Parenthood, feeding officers on the ground real time information.

“A little different from Columbine. Columbine was 260,000 square feet and we didn’t have that floor plan coming into us. That was one of the biggest lessons learned. Now you can almost have it downloaded to your phone,” said DeAndrea, comparing the two incidents.

All are changing tactics aimed at saving lives as tragedies like the one in Colorado Springs become much more common.