(CNN) A US prosecutor said Tuesday that a teenage girl who allegedly plotted to kill her best friend also shared child pornography videos of other victims with her co-conspirator.
Denali Brehmer, an 18-year-old from Anchorage, Alaska, has been indicted in federal court on charges of conspiracy, production and distribution of child pornography, and will face first-degree murder and other counts in state court.
Brehmer is accused of luring Cynthia Hoffman, 19, on a hike June 2 and shooting her in the back of the head.
Authorities say she plotted online and by text with Darin Schilmiller, 21, who court documents say is from New Salisbury, Indiana. He allegedly posed online as a millionaire named "Tyler," and offered Brehmer at least $9 million to kill Hoffman and send him "videos and photographs of the murder," according to the Alaska Department of Law.
Federal court documents allege Schilmiller had also directed Brehmer to sexually assault an "8- or 9-year-old" and a 15-year-old and send videos to him. Brehmer told investigators she did, and video of the 15-year-old was recovered by investigators.
The US Attorney for the District of Alaska, Bryan Schroder, had a warning for the parents of teenagers.
"For all of the good the internet can do, it can be a dark place and parents would be wise to monitor the activity of their children online," he said.
Brehmer faces up to 30 years if convicted of conspiracy to produce child pornography, 30 years if convicted of production of child pornography and 20 years if convicted of distribution of child pornography.
CNN has reached out to Brehmer's attorney, Emily Cooper, but a request for comment has not been answered.
Schilmiller faces production, conspiracy and receipt of child pornoraphy charges, and an additional charge of coercion and enticement of a minor. If he is convicted of that count, he faces a mandatory minimum of 10 years in prison with a maximum sentence of life.
It is unclear whether Schilmiller has an attorney. He is awaiting extradition from Indiana, officials said.
Brehmer and Schilmiller began discussing "a plan to rape and murder someone in Alaska" several weeks before Hoffman's murder, according to court documents.
Hoffman, 19, and Brehmer are described in the documents as "best friends."
Hoffman was bound with duct tape, shot in the back of the head, and pushed into a river near a hiking trail outside Anchorage on June 2, the Alaska Department of Law said in a statement.
Anchorage Police officers discovered her body along the Eklutna River bank on June 4.
Brehmer recruited Kayden McIntosh, 16; Caleb Leyland, 19; and two juveniles to help her carry out the killing, and in exchange, "all of them would receive a significant sum of money for their part in the planning and/or execution of the murder," according to the department's statement.
Hoffman was brought to Thunderbird Falls by Brehmer and McIntosh in a truck borrowed from Leyland under the ruse they were going on a hike near the Eklutna River, the statement said.
They stopped at a clearing and Hoffman's hands and feet were bound with duct tape, and duct tape was wrapped around her head and mouth, according to court documents.
McIntosh shot Hoffman one time in the back of the head with Brehmer's gun, court documents said, and she was then put in the Eklutna River.
Phone records show Brehmer was sending videos and photographs to Schilmiller "at his directive" throughout.
Hoffman's father, Timothy Hoffman, told CNN affiliate KTVA that his daughter had a learning disability.
Hoffman said in court his daughter was an "angel" and a "daddy's girl."
A state grand jury indicted all six defendants Friday for first-degree murder, first-degree conspiracy to commit murder, and two counts of second-degree murder and other charges. McIntosh is being charged as an adult.
Brehmer, McIntosh, and Leyland are in the custody of the Department of Corrections and will be arraigned Tuesday, according to the Alaska Department of Law.
The juvenile defendants are also currently in custody, the Department of Law said.
CNN has reached out to Leyland's attorney, Claire DeWitte, but a request for comment has not been answered. McIntosh's attorney, Ben Muse, was unavailable for comment Monday.