When two disturbed teenagers, Dylan Klebold and Eric Harris, attacked their classmates at Columbine High School near Denver in April 1999, the nation's worst school shooting opened the eyes of many in law enforcement to how unprepared they were for this new kind of threat.
Although police arrived within four minutes after the boys began their slaughter, it was 42 minutes from the start of the shooting until the first police entered the building. Fifteen people died that day, including Klebold and Harris.
"I'm not blaming the police; they did exactly what they were trained to do," said David Burns, an instructor with the Advanced Law Enforcement Rapid Response Training Program. "But we figured there was a better way to respond."
In a typical hostage situation, gaining control of the perimeter and setting up a command center make sense.
"But now we have seen the advent of violence where these people were building suicide into their plan," said San Marcos Police Chief Steve Griffith, director of the ALERRT Program. "They are going to create as much damage as they can before they commit suicide. You simply don't have time to get a SWAT team to the scene. So we give the officers the tactics to deal with it."
The ALERRT Program is a cooperative effort by the Hays County Sheriff's Department, San Marcos Police Department, Texas Tactical Police Officers Association, Texas State University-San Marcos and Texas A&M's Texas Engineering Extension Service.
While the program sprang from a reaction to the jump in school shootings, the two-day training course is equally applicable to possible scenarios involving terrorists, Griffith said.
He said he has found no other comparable course being offered in the United States.
In two years, more than 2,100 police in 100 classes have been trained, and demand continues to grow, Griffith said.
ALERRT has a training facility in San Marcos, but the trainers often take the course on the road.
Wednesday, Burns and three other instructors were giving the second day of training to 18 military police from Fort Sam Houston at an abandoned elementary school in the Edgewood School District, making the class as realistic as possible.
They even use real Glock handguns, except they've been refitted to shoot only 9 mm plastic balls filled with colored soap. Unlike a typical paintball gun, the Glocks fit in the officers' gun holsters; and they fire the bullets at 450 feet per second, compared with a typical paintball gun's maximum of 300 feet per second.
Possibly the hardest thing about the course is officers have to train themselves to sometimes do the opposite of what their first reaction normally would be.
For example, at one point the class was being trained on what to do if someone was throwing pipe bombs at them.
If a bomb is going to land within 10 feet in front of them, the correct response is to charge.
"I know it sounds crazy, but charge him and kill him," Burns said. "I know that doesn't sound politically correct, but it is imperative. You have to take him out."
Later in the day, teams of four or five officers took part in various scenarios.
They were given sketchy information: At least two gunmen were seen entering a school.
In one run-through, the team of four entered the main hallway to see one person halfway down the hall, on the ground, calling for help.
As they approached, a gunman walked out of a doorway, turned his back on them and walked toward another room at the far end of the hall. A second gunman lay in wait in a room near the injured person.
Would the team members shoot the first gunman in the back or let him get to the other room? Would they be so fixated on the gunman walking away that they wouldn't spot the second one in time?
The first team shot twice at the gunman after he ignored their commands, but both shots missed. They did a good job spotting and taking down the second gunman.
When they reached the end of the hall, three members did a Three Stooges maneuver trying to pile through the doorway at the same time.
A second team, confronted with the same scenario, opened fire, hitting the first gunman in the back several times.
Burns asked why they fired at him, since the man walking away did not appear to be an immediate threat.
"He's walking around with a gun," one of the officers said. "He's already shot someone. He's not listening to our commands. I'm taking him down."
Burns said that was the right decision, considering the totality of the situation and the threat the gunman posed to others if he made it to the second room.
The goal of the training, Burns said, is to give officers a frame of reference to draw on in an emergency, so they don't freeze for even an instant.
"Gunfights are not won or lost in seconds," he said. "They are won or lost in a fraction of a second."
Those who have taken the training say it is unlike any exercise they've been through.
"The ALERRT training was head and shoulders above what we have had," Texas Ranger Capt. Kirby W. Dendy said. "Between terrorism and the probability of more Columbine-type situations, this training is extremely appropriate for the environment in which we are living and working today."