A string of attacks on cities, schools and workplaces has prompted many employers to turn to a new area of security for their employees: active-shooter training. Until about a decade ago, workplace security focused mostly on preventing theft. Now, businesses are trying to give their employees guidelines on how to escape or handle armed intruders. "Active shooter's been kind of my life since 1999," says James McGinty, vice president of training and development for Covenant Security Services, whose clients include companies looking for guidance on how to deal with active shooters. He is also a former police officer and consultant to the Department of Homeland Security. "Seventy-five to 80 percent of your businesses are looking to now do some type of armed intruder/active shooter policy procedure and training," McGinty says. He says the Columbine High School shootings in 1999 changed the way law enforcement, schools and workplaces thought about dealing with an active shooter. Definitions of what constitutes an active shooter can vary, which makes data hard to collect. Some crowdsourced estimates put the number of shooting events last year at 330, but some definitions only include events with four or more casualties. The FBI defines it as someone actively engaged in killing or attempting to kill people in a confined and populated area. There were 160 such incidents between 2000 and 2013. Insurance companies may encourage employers to do active-shooter training to limit liability. Some in the chemical or nuclear power industry might be required to do so by law. It is also a sensitive matter — no company was willing to discuss its program on the record for this story. Some employers partner with local law enforcement for their training. Videos produced by local police forces and the Department of Homeland Security promote the slogan "Run, Hide, Fight." They say running away increases the chances of survival. They also advise coming out of the building with your hands up, or turning off the lights and your cellphone ringer if you're hiding. Or — as a last resort — trying to gang up as a group on the assailant. This kind of training at work is hard, says Laurence Barton, a threat consultant and trainer who works with the FBI. "How do you create awareness, without creating paranoia?" he says. He says employers are handling more threats — increasingly made through social media or through underground Internet services that allow people to send anonymous, encrypted messages. "About a dozen threats per week for the Fortune 100 [companies] is average," Barton says, but the vast majority of those are handled quietly, without incident or publicity. It often falls to human resources departments to identify unstable or problematic employees — and sometimes fire them. They have to weigh a worker's medical privacy and rights against the safety of other workers. Barton worries that some training courses create false expectations that those workers can handle active shooters themselves. "This cottage industry is out offering one- and two-day seminars on how to deal with the active shooter, and this is crazy. This is absolutely, in my opinion, totally inappropriate," he says. Only police, he says, should manage shooters. Don Alwes, a law enforcement officer and instructor for the National Tactical Officers Association, says workplace training does not have to be expensive or time consuming, especially when done in concert with local police. "The training costs on that are relatively low, compared to some types of physical security systems or armed guards," Alwes says. But none of it is effective if people don't heed the lessons from past shootings. "Sometimes we learn the lessons, but they tend to fall out of our minds as we get back to normal activities," he says. "Someone paid for those lessons, usually in blood." The San Bernardino facility attacked in December conducted monthly active-shooter trainings. One might be tempted to say it didn't work, but Alwes says it's hard to know. More might have died that day without it.