The training exercise called for the use of modified guns with paint bullets as ammo, but deputies learned real-life tactics that could save lives.
"When a shooter is actively shooting, every 15 seconds someone is dying," said Shane Millhollon, a deputy with the Orange County Sheriff's Department.
The OCSD started the special training after the massacre at Columbine High School in 1999, when two teens murdered 12 students and a teacher, and left several others injured.
"With the Columbine incident, that was traditional police tactics: show up at a scene and secure it and wait for the SWAT team," Millhollon said. "Our tactics today are a little more dynamic."
Officials said patrol deputies, typically the first on the scene, are learning SWAT techniques so they can move in sooner to handle a shooter if there isn't time to wait for SWAT to arrive.
"If we don't have this type of training, we're really behind," Millhollon said.
Authorities said learning the latest tactics is more important than ever given the recent shootings. On Thursday at Taft Union High School in Kern County, a 16-year-old boy was suspected of opening fire in a classroom, leaving one student critically injured. Last month at Sandy Hook Elementary School in Newtown, Conn., a 20-year-old man was accused of shooting and killing 20 children and six adults.
"If we don't have a timely response to a deadly situation like that more lives are going to be lost," Millhollon said.
Officials said they want all patrol deputies to receive the specialized training by the end of 2013.