What should you do in an active shooter situation?

WASHINGTON - There have been 355 mass shootings in the United States so far this year. But have you thought about what you would do if a gunman barged into your office or workplace?

FOX 5's Paul Wagner spoke with Sgt. Charles Smith of the Maryland-National Capital Park Police about this situation. He is an expert who has taught other law enforcement about active shooters and he has spent ten years as the head of SWAT in Prince George's County. Here are some tips to help you in case of an active shooter situation.

1. Create an evacuation or hiding plan

Discuss with your co-workers on where the best places you can go or which exits you can use in order to get out of the building quickly. And if you are unable to, figure out what locations would make for good places to hide.

2. Run, hide or fight

"The first thing is to run, to get away from it, to escape the situation," Sgt. Smith said. "The second thing is, if you can't do that, try to hide somewhere, try to barricade yourself. Go to an area where you can lock yourself away. Put a barrier of some sort between you and this active threat."

When hiding, Sgt. Smith highly recommends knowing the difference between cover and conceal.

"If you have cover, you can maybe be protected from gunfire. If you just have mere concealment, you may not be seen, which may be enough, but remember, it's not going to prevent rounds from coming through whatever it is, so you need to understand that."

If running and hiding are not an option, Smith said fighting for your life should be your last resort.

"Anything you have at your disposal to use, you use it -- if it's a printer, if it's a telephone you can throw. Keep a small baseball bat in your office. I don't think any employer would care. It would be something that you would have readily available to at least be able to strike. Get anything that you have available to distract these folks. Throw things at them if you have to run at that point."

3. Take your cell phone with you

If you are able to, you should contact authorities as soon as possible.

"If you have a cell phone handy or you have your work phone, call law enforcement," said Smith. "Let them know what's happening. Give them information that will assist them in being successful and making that entry and eliminating that threat."

If you are inside a closet and believe the shooter is nearby, Smith said do not call, but instead use text messaging if it is safe.