"Schilmiller offered Brehmer nine or more million dollars to carry out the murder and to have photographs and/or videos of the murder sent to him".
"Several weeks before Hoffman's murder, the two began discussing a plan to rape and murder someone in Alaska", the documents said.
Brehmer then recruited four of her friends - 19-year-old Caleb Leyland, 16-year-old Kayden McIntosh, and two others who are too young to name - to help commit the murder.
Once the group stopped at a clearing, Hoffman's hands, feet, head, and mouth were bound by duct tape, and McIntosh shot her once in the back of the head with Brehmer's gun.
Hoffman's body was pushed into the Eklutna River and the teens try to burn her body before sending text messages to Hoffman's family making out she had been dropped off elsewhere, the charge sheets says.
Eventually Schilmiller offered Brehmer at least $9 million for "videos and photographs of the murder" of 19-year-old Cynthia Hoffman.
Hoffman had a learning disability, according to CNN.
Brehmer said that at some point, McIntosh took a gun from her and shot Hoffman before pushing her into the river.
Four Alaska teenagers, including 16-year-old Kayden McIntosh and 19-year-old Caleb Leyland, both of Anchorage, and 21-year-old Darin Schilmiller, of IN, were also indicted on the same charges.
Schilmiller also allegedly instructed Brehmer to rape an "8 or 9 year old" and a 15-year-old, with similar request for video evidence.
A grand jury last Friday indicted all six defendants for first-degree murder, conspiracy to commit murder in the first degree, two counts of second-degree murder and other charges.
The juvenile defendants are also now in custody, the Department of Law said. Schilmiller is being extradited to Alaska to face the charges.
Digital evidence showed that Brehmer was communicating with Schilmiller throughout the duration of Hoffman's murder, according to police. The victim was described as Brehmer's best friend.
Both face up to life in prison on child pornography charges.
In a criminal complaint, FBI Agent Jessica Hais said Schilmiller directed the recording of sexually exploited girls by Brehmer, 18, of Anchorage.
In interviews, she referred to him as "Tyler" from Kansas.
Brehmer, McIntosh and Leyland are now behind held by the Department of Corrections and will be arraigned on Tuesday, the department added. It has a policy of not commenting on pending cases.
Online court records do not list his attorney who could comment on the case.
Schilmiller also stated that he chose Hoffman as the victim.
In addition, Schilmiller admitted he and Brehmer discussed murdering another person after Hoffman, "but that the plan was ultimately abandoned", the documents said.
Brehmer has been charged with first-degree murder for Hoffman's death.
Bryan Schroder, Alaska's U.S. Attorney, right, in a file photo from Wednesday, March 27, 2019, in Anchorage, Alaska, announced indictments against Darren Schilmiller and Denali Brehmer on Tuesday, June 18, 2019.
Hoffman "worked in restaurants but truly enjoyed being her dad's right-hand man in his handyman business", according to her obituary. "She is truly going to be missed".