Details are being released about a robbery that took place Friday evening at a Casper movie house.

According to Casper Police Sgt., Jim Wetzel, the suspect entered Downtown Casper's Rialto Movie house just after 7:00 pm, displaying a small black, semi-automatic handgun, and demanding money from the clerk at the theater's concessions counter. The suspect then fled on foot.

A customer exited the theater, and saw the clerk lying on the floor, as instructed by the suspect, and police were notified.

The suspect is being described as a lone Caucasian female.

"She was wearing, what appeared to be, black bib snow pants, black jacket, possibly layered with a black hoodie," Sgt. Wetzel says.  "Appeared to have a black stocking ski mask that was rolled up on her head."

At this time, says Wetzel, investigators do not have reason to believe that the suspect was acting with any accomplices.

Police hope to release a photo of the suspect soon.

Anyone with information about the crime or the identity of the suspect is asked to contact the Casper Police Department.