ELKO, Nev. -- A Nevada high school senior accused of killing a popular female classmate and burying her in a shallow desert grave near the Utah line told police he struck her on the head and neck with a shovel during an argument.
Kody Patten was scheduled to be arraigned in Elko Justice Court Wednesday afternoon on a charge of open murder with the use of a deadly weapon in the beating death of 16-year-old Micaela "Mickey" Costanzo.
Costanzo was last seen leaving her West Wendover school after track practice Thursday. Her disappearance brought out more than 100 volunteers in a search around the eastern Nevada gambling town on Friday and Saturday.
Signs of the grave were discovered about five miles from the Utah-Nevada border on Saturday, and authorities on Sunday confirmed that it contained Costanzo's remains.
The 18-year-old Patten initially agreed to be interviewed by detectives on Friday after investigators determined he was the last person to telephone or send a text message to Costanzo before she disappeared, Elko County Sheriff's Det. Kevin McKinney said in a criminal complaint filed by prosecutors.
At first, Patten denied any knowledge of what happened to her. But McKinney said he changed his story after police told him he'd been seen on school surveillance video and that a tire track at the scene of the crime matched a tire on an SUV that Patten said earlier he had borrowed from a friend on Thursday.
On Sunday, after Costanzo's body had been recovered and tentatively identified, McKinney said Patten spoke to his father and waived his Miranda rights before acknowledging his role in her death. He's been held in the county jail without bail since his arrest early Monday.
Patten described how they had argued before he pushed her down and she first hit her head on the bumper of the borrowed Chevy Trailblazer, McKinney said in the complaint. After more arguing, Patten said he pushed her down again and she hit her head on a rock, McKinney said.
Patten told the detective she then suffered a seizure, and he became panicked and swung a shovel at her head, striking and cutting her neck with the sharp edge of the shovel, the complaint said.
Patten then acknowledged he had buried Costanzo to conceal the body, McKinney said.
Court officials said Patten has petitioned for a public defender. A spokeswoman for the Elko County Public Defender's office said Wednesday that chief public defender Fred Lee wasn't immediately available to comment.
Patten and Costanzo knew each other as students at West Wendover High School, which has an enrollment of about 300 students, vice principal Craig Kyllonen said. He said Patten had talked of trying to enlist in the military after graduation later this year. School officials have released few other details about him.