Denali Brehmer, 18, and 16-year-old Kayden McIntosh were previously charged with first-degree murder, police said. Leyland, who told police he provided Brehmer and McIntosh with a vehicle, faces charges of first-degree murder and first-degree conspiracy to commit murder, authorities said.
Leyland also told officers that he, McIntosh, Brehmer and the male and female juveniles agreed to kill Hoffman near Thunderbird Falls in the Chugiak area, 27 miles (43 kilometers) northeast of Anchorage.
The male juvenile said McIntosh and Brehmer came to his house June 2 and told him they "had shot Hoffman and killed her," police said. Investigators found Hoffman's body June 4 in the Eklutna River where Brehmer told authorities the killing occurred after they told Hoffman they were going for a hike. Hoffman's feet were duct taped together, police records said.
Brehmer told police she directed McIntosh to use a 9mm handgun she was carrying to shoot Hoffman in the head, while McIntosh said shooting Hoffman was Brehmer's idea and that she fired the gun, police said.
Two Snapchat videos were turned over to police Thursday by a friend of Brehmer. The first video shows Brehmer describing the story she later gave to police; the second video includes Brehmer apologizing to her family and friends and saying, "I'm sorry, I didn't mean to do it," police records said.
The Daily News reports that when the two teens were initially questioned by police, they told detectives that the trio had decided to duct tape each other and take photos near the popular Thunderbird Falls trail, in the Chugiak area.
According to their accounts, Hoffman started panicking after she was bound. At that point, Brehmer originally told detectives, McIntosh took the gun from her hand and shot Hoffman in the head with it before pushing the 19-year-old's body into the Eklutna River.
Hoffman's father, Timothy, told the Daily News on Saturday that his daughter met Brehmer when they were both students at Service High School. Cynthia Hoffman had described Brehmer as her "best friend," he said.
He said a developmental disability that caused his daughter to operate intellectually at about a seventh-grade level had made her vulnerable. "Her disability just made her want to have friends," Timothy Hoffman said. "That's all she wanted, was just to be her friend."
Information from: Anchorage Daily News, http://www.adn.com