An 18-year-old in McAlester, Oklahoma was arrested Monday after she told co-workers that she was allegedly planning to "shoot 400 people for fun" at her old high school.

Alexis Wilson was taken into custody by the Pittsburg County Sheriff's Office for a felony terrorist hoax, reported McAlester News-Capital, for threatening a mass shooting at McAlester High School.

Wilson had also shown co-workers pictures and videos of her holding an AK-47, saying to them that she wanted to gun down hundreds and "that there were so many people at her old school that she would like to do it.”

She tried to convince her co-workers that not all gun owners are bad people, the News-Capital said.

Wilson was expelled from McAlester High after being caught with a knife and a swastika at school multiple times. An affidavit obtained by NBC News says that she experienced bullying when she attended the school, and was unable to reenroll.

Deputies found an AK-47 and a shotgun in her bedroom, along with additional magazines for the assault rifle.

McAlester High School received extra security as a precaution to the threat, district Superintendent Randy Hughes told the News-Capital.

Wilson is currently being held on a $250,000 bond at the Pittsburg County Jail and could face up to 10 years in prison.

Contributing: The Associated Press. Follow Joshua Bote on Twitter: @joshua_bote