Gunfire from above. A sniper, according to Dallas Police, a frightening and deadly encounter downtown Dallas.
In San Marcos on Friday, Dr. Pete Blair with ALERRT called the event "terrible."
"When we found out that they're targeting law enforcement officers and that many law enforcement officers were killed... obviously that has a large impact on us as well. And, you know, we don't know the names of everybody yet but there's a good chance that if we don't have a direct connection to somebody there then certainly we know somebody who worked with the officers that were killed," Blair said.
Blair is the Executive Director of Advanced Law Enforcement Rapid Response Training Center or ALERRT at Texas State University. The program started in 2002. Since then they've trained more than 85,000 law enforcement officers across the country on how to respond to active shooters.
Blair says it's too soon after the event to really analyze everything that happened...
"From what we've seen so far it looks like they did what they were trained to do which is...their first priority is to go stop the killing, to go to that shooter, to go to the sounds of gunfire and try to isolate, distract or neutralize the attacker," Blair said.
Both Dallas P.D. and DART Police have gone through some ALERRT training according to Blair.
"People need to train for these events because they are rare events, they don't experience them every day, they're highly critical and the way to prepare for them is to do training," Blair said.
Hours after the initial ambush, one tactic that took many by surprise using what the Dallas Police Chief referred to as a "bomb."
"We cornered one suspect and we tried to negotiate for several hours. Negotiations broke down, we had an exchange of fire with the suspect. We saw no other option than to use our bomb robot and place a device on its extension for it to detonate where the suspect was," said DPD Chief David Brown.
Dr. Blair says that tactic and any other robotics aren't part of ALERRT. He believes the "bomb" was actually a breaching charge that SWAT teams use to get through doors.
Blair says with each active shooter situation, ALERRT looks back at the lessons learned.
"Certainly an event like this that appears to be multiple attackers and an ambush-style opening because of the attack targeted at police, I'm sure that there are lessons that we'll learn from this event that we can integrate into our training," Blair said.