Matthew Liewald, 15, sobbed as prosecutors played the tape where Liewald could be heard saying, "It was me that pulled the trigger."
He said repeatedly he was afraid of his father and had planned to run away from home. He decided the only way he could do it would be to kill his father.
"If my dad found me, it would be worse than dying," he told investigators.
So he told them he found two pistols, a knife and a shotgun in their home and waited for Christian Liewald to come home.
"I was hoping he wouldn't get me, the 15-year-old said. "And when they got around the corner, I started shooting."
Prosecutors said the act was premeditated and deliberate. The judge called the slaying a tragedy for everyone involved and ordered Liewald to stand trial as an adult.
The teen told detectives that he had been grounded because he missed his curfew after spending the day at Scarowinds, the Halloween-branded activities at the Carowinds theme park. That made him angry and scared, he said in the interview.
He also said in the taped interview with detectives he never meant to kill his stepmother. Liewald told investigators he waited in the hallway for his father, 43-year-old Christan Liewald, to come home and then opened fire.
The officer who first responded to the scene testified in the hearing and described finding 15-year-old Liewald sitting at the entrance to the neighborhood.
Defense attorneys have argued that the boy's father had been abusive for years. They said the teen was desperate and afraid and not thinking clearly.
Liewald's mother, who has not seen the boy in nine years, struggled to hold back the tears as she left the courtroom.
Other members of Liewald's family expected the outcome, but were clearly upset as they left the courthouse. None of the family members commented after the hearing.
Previous Stories: September 29, 2011: Teen accused of killing father, stepmother makes court appearance September 27, 2011: Homicide suspect's mother says warning signs were there September 26, 2011: Neighbors react to teen shooting father, stepmother September 26, 2011: Police identify couple killed, charge teen with their murder