A southern Indiana man and five teens from Alaska have been indicted on federal murder charges after officials say they planned, carried out and recorded the slaying of Cynthia Hoffman in early June.

According to a news release from the Alaska Department of Law, an Anchorage grand jury indicted 21-year-old Darin M. Schilmiller of New Salisbury, Indiana for murder in the first degree, conspiracy to commit murder in the first degree and two counts of murder in the second degree.

Also charged are 18-year-old Denali Brehmer, 16-year-old Kayden McIntosh, 19-year-old Caleb Leyland, and an unnamed juvenile male and juvenile female. All of Schilmiller's co-defendants are from Anchorage, and McIntosh is being tried as an adult.

In addition, Schilmiller and Brehmer were each indicted on a count of solicitation to commit murder in the first degree; Brehmer and McIntosh were also indicted for tampering with physical evidence.

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Brehmer faces one count of tampering while McIntosh faces four.

Court documents say Schilmiller offered to pay Brehmer $9 million or more to carry out the murder and send him videos and photos of the crime. He first met Brehmer online while posing as a millionaire from Kansas named Tyler.

Police learned that Schilmiller had been lying to Brehmer about his identity for several months, court documents said. Weeks before Hoffman was killed, the pair began discussing a plan to rape and kill someone in Alaska, according to court documents.

Brehmer recruited her friends McIntosh, Leyland and the two juveniles to help with the planning and execution of the murder, court documents said. Brehmer agreed to pay her recruits a "significant sum of money" for their cooperation.

Throughout the month of May, the teens worked on their murder plan, court documents said. After some discussion, the teens chose Hoffman, who was allegedly "best friends" with Brehmer, as their victim.

Court documents said Hoffman was taken to Thunderbird Falls by Brehmer and McIntosh in a truck borrowed from Leyland. They told the victim that they were all going to hike on the Eklutna River.

Once they made it to a clearing, Hoffman's hands, feet and mouth were bound with duct tape, police said. McIntosh is accused of firing the shot that killed the 19-year-old. Her body was dumped in the river.

Court documents said that Brehmer sent videos and photos to Schilmiller during the crime.

Hoffman's clothes, cell phone and purse were destroyed by Brehmer and McIntosh, court documents said. Brehmer also texted Hoffman's family after the shooting and said that Hoffman had been dropped off at a park in Anchorage.

While initially denying any knowledge of the plan, Brehmer eventually told police that she was solicited by Schilmiller to kill someone, court documents said. Collected evidence includes a Snapchat video in which Brehmer appears to confess, police say.

Federal agents and members of the Indiana State Police made contact with Schilmiller on June 9. He admitted to posing as "Tyler" and misleading Brehmer, who went by the name "Angel" online.

He told police that they spent three weeks planning the murder and that he chose Hoffman as the victim. Schilmiller said Brehmer communicated with him during the crime via Snapchat, and that she sent him photos and videos of Hoffman tied up, and her body after she was killed.

Court documents said that Schilmiller further admitted to discussing a second murder with Brehmer, and that he attempted to blackmail Brehmer after the murder to force her to sexually assault people.

If convicted, the defendants face up to 99 years behind bars for each of the murder charges, the conspiracy to commit murder charge and the solicitation to commit murder charge. Brehmer and McIntosh also face up to five years for each of the tampering with physical evidence charges.

Schilmiller has been arrested and he is awaiting extradition to Alaska.

Brehmer, McIntosh, and Leyland are in the custody of the Alaska Department of Corrections and will be arraigned Tuesday morning. The two juveniles are also in custody.

Call IndyStar reporter Justin L. Mack at 317-444-6138. Follow him on Twitter: @justinlmack.