Officers responded around 3:30 a.m. to a report of possible gunshots at Bella One, an adult business located at 25W319 Lake Street. They found a male body at the scene.
Chopper 7HD was over the scene later Friday morning. The victim's body was seen lying at the bottom of a set of stairs leading to an entrance to the parlor.
Sgt. Robert Harris, public information officer for the sheriff's office, told ABC7 Eyewitness News partner the Daily Herald the victim suffered gunshot wounds and the incident stemmed from a fight between a customer and a security guard.
Investigators said the incident was isolated and a person of interest was identified after a short time. That person is in custody and is being questioned at the sheriff's office.
The investigation is ongoing.