An 18 year old man arrested Monday morning is scheduled to appear in Yellowstone County Justice court.
Mason Ray Loughnane faces a misdemeanor charge of possession of a BB gun, drug possession and theft as well as a felony drug charge.
At around 4 am Monday morning police dispatchers arrived at West high school after receiving a complaint.
A man working at the school observed Loughnane on the premises and became suspicious of his odd behavior.
The man entered his vehicle to call 9-1-1 but realized his phone was missing.
When police officers arrived on scene they discovered two brown BB guns, methamphetamine and THC.
If convicted of the felony charge, he faces up to five years in jail and if convicted of the three misdemeanor charges, he faces up to six months per count in jail and a fine.
The investigation is still ongoing.