DEER LODGE, Mont. — For years, the old prison in Deer Lodge, Montana operated as the state's maximum security prison, but it has also had a reputation of being haunted.

That's what drew the Spokane Paranormal Society to the area. Started in 2015, the small group investigates haunted locales, not just for their own curiosity, but to help potentially remove the haunting ghosts.

"We knew we caught something. We knew we had some evidence from this place," said Spokane Paranormal Society member Mark Porter.

The old Montana State Prison opened in 1871 in Deer Lodge and operated for 100 years before it became a museum.

"This is probably one of the most haunted places in the Northwest," said Porter. "We want to help spirits move on. If they're stuck, they shouldn't be."

Porter said many spirits are stuck at the Montana Prison.

The group spent the night at the prison last Friday. There, Porter said he felt a ghost make contact with him and another member of the group.

"And there's nobody in the building but us on the fourth floor. And we heard it from below. But we heard a woman scream," said Porter.

The night vision camera captured what they call "orbs" or energy left from spirits.

A separate camera captured what they believed to be the outline of a ghost taking a shower.

"Our SLS camera works like an Xbox Kinect. It'll map out a spirit as a stick figure," Porter said.

The Spokane Paranormal Society investigated several other haunted Inland Northwest and Spokane as well. They said they do this to have a better understanding of the world of ghosts.