ANDERSON, S.C. >> A boy who was 14 when he was charged in the shooting death of his father at their home and a first-grader on a South Carolina elementary school playground will be tried as an adult, a judge ruled today.

The decision from Family Court Judge Edgar Long means Jesse Osborne, now 15, could face decades in prison if convicted of murder. If he had been tried as a juvenile, he could have been kept behind bars only until his 21st birthday.

Prosecutors treated the hearing like a mini trial. They played an interview the teen gave to investigators hours after the September 2016 shootings where he said he was angry at his father before the shootings started. The principal of the school testified at the horror she felt when she recognized Osborne as a former student.

And two psychologists testified that Osborne showed no remorse and was a danger to commit more crimes if he were treated as a juvenile and released from jail after several years. One said the teen enjoyed thinking about killing people.

Osborne said he loaded the wrong ammunition into his gun before going to Townville Elementary School after killing his father, and the gun jammed after every shot. He said he felt like the gun jamming was God’s way of making sure more people weren’t killed.

Along with the teen’s father, 47-year-old Jeffrey Osborne, Jesse Osborne is charged with killing 6-year-old Jacob Hall at the school. The boy was shot in the leg and bled to death. A teacher was wounded in the shoulder and another student was hurt, but both survived.

Osborne is also charged with three counts of attempted murder and five counts of possession of a weapon during the commission of a violent crime.

Defense attorneys argued that Osborne wasn’t old enough to be held responsible like an adult. They asked questions about the teen’s home life. Osborne said in his confession his father and mother often had angry, drunken arguments and he locked himself in his room, petting his rabbit or posting on social media.

Clinical psychologist Dr. Danielle Atkinson testified that Osborne could be rehabilitated, but there is no idea how long that could take. Atkinson added that the teen says he is sorry for the killings, but does not show physical signs of remorse and doesn’t seem to grasp the seriousness of the shootings.

Osborne told investigators he was being homeschooled after he brought a machete and hatchet to his middle school. Prosecutors showed pictures of his room, full of electronics and several video game systems with several versions of the shooting games like “Call of Duty.” Investigators testified that he searched the internet on topics like “youngest mass murderer” along with mass shootings at an Orlando nightclub, Sandy Hook Elementary School in Connecticut and Columbine High School in Colorado.

One of the detectives asked Osborne hours after the shooting if his ultimate goal was to kill himself.

“I was just done,” Osborne replied. “And I was like, OK, I can’t take all this hatred anymore. So I was like, yeah, I might as well kill myself before I go to jail. But I’m glad I didn’t, because now I have a life — probably won’t get a job — but I’ll at least have a life.”

Osborne didn’t seem to grasp the severity of his crimes as he was being questioned. He once suggested he should be released when he turns 18, asked if along with murder he might be charged with driving his father’s truck to the school while being too young to have a license and asked several times if he would be held at the juvenile jail in Columbia where he spent a few weeks after brining the weapons to the middle school.

“I really hope I get sent to Columbia, because there’s an actual school there. That might actually help me because I haven’t studied at all — forever — just studied what I want to study,” Osborne said.