VISTA —— Councilman Steve Gronke shouted at the young man with a gun threatening students in a school library, telling him repeatedly to drop his weapon. Suddenly the man fired his gun, hitting a student as Gronke reacted and shot at the man, less than a second too late.

The scenario wasn't imaginary, but wasn't quite real either —— it was part of a computer-simulated training exercise at Vista City Hall on the use of force Tuesday evening. Four of the city's five council members participated: Mayor Morris Vance, Councilwoman Judy Ritter, Councilmen Gronke and Frank Lopez.

Council members called the exercises "eye opening," especially in light of three recent fatal shootings by sheriff's deputies in Vista. Residents who discussed the shootings at a recent community forum expressed outrage and criticized the use of force by deputies.

"Since the shootings, I have had a lot of questions from local residents on the use of force, and I can honestly say this (exercise) is not as easy as people might expect," Gronke said. "Movies and TV are so awful, it's really not like that at all."

Sheriff's officials said Tuesday they planned to allow members of the public to use the simulator, or one like it, at an open house at the sheriff's station in the future.

"It will be a good experience for the public to interact with the program and see some of the difficult decisions you have to make in those situations," said Capt. Rob Ahern.

The $25,000 firearm training simulator, or FATS, was set up in a darkened City Hall chambers. Participants had to wear light bulletproof vests and give verbal commands to subjects in a variety of scenarios, from traffic stops to hostage and suicide settings.

The council members were armed with a modified handgun, nearly identical to the standard-issue Glock 22 carried by deputies. The gun weighs the same as the deputies' weapons, but was modified to fire simulated rounds recognized by the computer. In certain scenarios, the gun recoils the same way a real weapon would, courtesy of an air-compression system connected the firearm.

Deputies T.J. Byrne and Phil Beaumont guided officials through the exercise.

"Shooting the gun out of someone's hand, it's just not that easy," Byrne said, after Gronke asked about trying to disable a suspect with a shot. "It's pretty much impossible. TV is one thing, but reality is another."

The simulator was bought by the city about a year and a half ago and is used once or twice a year by city officials, said Assistant City Manager Rick Dudley. He said the city plans to set up the simulator in a classroom permanently once a new City Hall is built.

"We are peace officers, and part of keeping the peace is to protect everybody," said Byrne, after Ritter didn't shoot at a computerized suspect bludgeoning another man in one simulation.

"It all happens in a split-second, your adrenaline is going and you have to make such a fast decision that I just couldn't do it," Ritter said after the exercise was complete. "I couldn't get in there."

Overreaction, Byrne said, is a more typical response from civilians who use the program.

"Most people wind up using too much force," he said. "They perceive danger where there may not be, but that's what we're trained to evaluate."

Contact staff writer Anne Riley-Katz at (760) 631-6622 or ariley-katz@nctimes.com.