A real-life Connecticut murder is the inspiration for a new movie in theaters Friday.

Patrick Wilson and Vera Farmiga are back as legendary paranormal investigators Ed and Lorraine Warren in the third installment of the Conjuring universe, "The Conjuring: The Devil Made Me Do It."

It focuses on a high profile case out of Brookfield - the 1981 murder trial of Arne Johnson.

"It’s said that Arne had a violent argument with this man, the kennel owner, and stabbed him," says the son-in-law of the Warrens' and New England Society for Psychic Research director Tony Spera.

Spera recalls Ed Warren calling this a "monumental case."

"I said 'What do you mean, Ed? Why is it monumental?' And he said because this is going to be a case where we’re going to claim the devil made this kid do it," he says.

The Warrens say Johnson had been inhabited by a dark force. He became the first defendant to plead not guilty by reason of demonic possession.

"He says all he can remember is standing in the backyard and the next thing he recalls he's in custody," says Spera. "To this day, Arne does not remember anything about the incident itself."

In real life, Johnson was convicted of manslaughter and served five years in prison. Spera isn't sure how things play out on screen.

"It's not a documentary, It's an entertainment piece, inspired by true events," says Spera.

The movie is debuting in theaters nationwide and is streaming on HBO Max. Spera hopes it’ll spark interest in another paranormal project he has coming up this fall - the first-ever Warrens' Seekers of the Supernatural Paracon in Waterbury on Oct. 30.

"There are a lot of paranormal conventions, paranormal conferences but this one is going to be honoring Ed and Lorraine Warren," he says.

Ed and Lorraine Warren have both died, but the artifacts from their investigations live on at the Warrens' Occult Museum in Monroe. The museum is currently closed, but its contents will be featured at Paracon.