HOPKINSVILLE, KY - Police have arrested another suspect in connection to the sexual assault that critically injured a 15-year-old boy in Hopkinsville.

Sam Miller, 18, was arrested in Louisville on Wednesday night. Police said he will be transported to Christian County on Thursday.

Miller, 19-year-old Tyler Perry, 20-year-old Dayton Jones and two 17-year-olds are all facing charges in the case.

Police said Miller, Perry, Jones and one of the juveniles took part in the assault, which was recorded and posted online via the social media app Snapchat. The other juvenile is accused of possessing a video of the act.

"Seventeen years I've been in law enforcement, and two of those years I did work child sexual crimes, and this is probably one of the worst I've seen," said Capt. Chris Miller with the Christian County Sheriff's Department.

Court records said the victim was incapacitated at a party at Sam Miller's Hopkinsville apartment and was sexually assaulted with an object.

The sheriff's department said they have been fortunate that several witnesses were at the party and are now being interviewed.

Perry and Jones were taken into custody without incident and booked in the Christian County Jail. The two juveniles were taken to the Christian County Designated Workers Office for processing.

Sam Miller, Jones and Perry face a long list of charges, including sodomy and use of a minor in a sexual performance.

Channel 4 has learned from court documents that Perry is a Marine reservist.

Investigators would not share details of the crime, only all involved knew the 15-year-old.

"We are still trying to see exactly why this would take place and why the videotaping was involved," Capt. Chris Miller said. "So that's obviously something ... we are going to try and figure out."

Jones and Sam Miller are both being held on a $1,000,000 bond, while Perry is being held on a $100,000 bond.

The victim is being treated for life-threatening injuries at a hospital in Clarksville.