What to do if there’s an active shooter at your workplace

A woman injured at least three people and died of a self-inflicted gunshot wound after a shooting at YouTube's headquarters in San Bruno, California on Monday. Last December, a shooting at a California law office left two dead. That same month, a gunman killed two, plus himself, in a Houston workplace shooting.

While office shootings are rare, they are increasing. According to a 2018 report from the Bureau of Labor Statistics, workplace shootings went up by 83 cases to 394 total from 2015 to 2016 and they comprised 79 percent of all workplace homicides in 2016.

In light of this, criminal response experts are urging employers and employees alike to prepare for the worst.

"It's helpful to recap sort of the three best practices in an incident like this," says Chad Sweet, a former Department of Homeland Security chief of staff. "The three things that we emphasize over and over is either get out, hide out or, if necessary, take the shooter out."

The DHS defines an active shooter as an individual who is "actively engaged in killing or attempting to kill people in a confined and populated area." According to the agency, these shooting situations quickly evolve and are highly unpredictable, so it's vital that you determine the best and most reasonable way to protect your life.

Most businesses have a security team that runs active shooting drills and alerts employees about unsafe situations. Although there is no set number on how often these drills should take place, they should occur as often as fire drills, says Diego Redondo, former FBI special agent and director of public safety and risk management at John Jay College of Criminal Justice. You may want to ask your HR leader if the company has a plan in place.

When you receive an alert about an active shooter on company premises, Redondo tells CNBC Make It that your first thought should be, "I need to get out of here."

Here are three steps you should take if there's an active shooter in your workplace:

Your best bet is to leave the premises, say both Sweet and Redondo, which is why it's crucial that you have an escape route and a plan in place before this type of incident occurs.

"You want to get away from wherever the shooter is," says Redondo. "Familiarize yourself with the closest exits so you can get away as soon as possible." This requires prior planning and preparation by looking at your company's floor plan and finding all of the closest emergency exits.

"Put in your head, 'what would I do if I had to escape right now?'" says Redondo.

According to the DHS active shooter response guide, you should help those around you, if possible. But evacuate regardless of whether your co-workers agree to follow you.

"As sad as it may sound, you just need to get out of there," says Redondo.

If you can't find an exit or "avenue of egress," you need to hide out and secure yourself in a safer space like an office, says Sweet. However, Redondo notes that hiding is simply avoiding being seen. This means that hiding out won't necessarily protect you from a stray bullet.

For example, if you're hiding behind a row of cubicles and there's a partition, a bullet can come through that opening and hit you. When hiding, Redondo advises that you look for a place that will also offer you coverage, such as a metal door, which is just as important as concealment.

Again, he says that choosing the perfect hiding spot requires prior planning. "Look at your particular office and determine how to barricade yourself or at least make it challenging for [the shooter]."

If you have an office with a door that swings inward, you can buy cheap $2 doorstops to stop someone from entering. If you have a door that swings outward, Redondo says that you will have to come up with other means of barricading yourself or find an office where you can lock the door from the inside. Once you've found a place to hide, get behind large furniture such as a cabinet or desk.

Additionally, make sure to have your phone completely silenced or turned off. Redondo explains that much in the same way a ringing phone alerts your attention, any sound will also grab the attention of the shooter. In most cases, shooters are looking to kill as many people as possible, unless they have a specific target, so they work quickly and move on.

The last thing you want is an incoming text revealing your location, he says.

Taking action against a shooter should be your last resort and only when your life is in imminent danger. Redondo warns that you should never go out in search of the shooter and advises that you leave that to the professionals. He puts it this way: Only interact with a shooter when your sole options are to get shot or take action.

The ex-DHS chief of staff points to the Parkland high school shooting in February where the shooter attacked individuals on room by room. In this type of scenario, "you need to take the shooter out," he says. "When you're faced with a life or death situation like that, you just have to find a way to incapacitate [the person]."

Sweet suggests arming yourself with something in the room that's readily available to you like a chair or a loose piece of metal. If you're hiding with a group of people, Redondo says that attacking the shooter should be a group effort. "Everyone should be going after the shooter at once." However, that doesn't mean attacking the shooter "martial arts style," he says, but rather grabbing close by tools that you can throw and use to disarm the person.

The DHS response guide adds that when taking out a shooter, you should do so as aggressively as possible and commit to your actions. Again, this is where planning comes in handy. The normal human response is to panic and freeze, says Redondo, but with proper preparation, you won't be "stuck like a deer in headlights."

Finally, creating an emergency strategy well in advance also saves you time. According to the public safety director, "time is the biggest enemy of an active shooter" because with today's technological advancements, law enforcement generally arrives in a matter of minutes.

"Every second of time you save increases the likelihood of your survival," he says.

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