DISCOVERY BAY, Calif. - A newspaper says a Northern California teenager has confessed to the fatal stabbing of a 9-year-old boy.

The Contra Costa Times reported Monday that William Schultz, 18, said he killed 9-year-old Jordon Almgren while the boy slept because he wanted to know what it felt like to murder someone before the world ended. The Times interviewed Schultz in jail.

"I wanted to see what it was like to take a life before someone tried to take mine," Shultz told the paper. The paper reported that he was smiling, spoke calmly and was wearing a yellow, jail-issued jumpsuit. He wore his hair in a buzz cut.

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Schultz was arrested Sunday on suspicion of murder in the case. He is being held on $1 million bail.

On Saturday, the day before the murder took place, Schultz had stayed the night at the victim's home in Discovery Bay, a waterfront community along the Sacramento-San Joaquin River Delta about 60 miles east of San Francisco.

He told the paper that his family had been concerned about his odd behavior and mental health over the last month and that he was briefly hospitalized Saturday in a county facility. He said a doctor discharged him and sent him in a cab to his mother's home where a fight between he and his mother ensued. He says that's why he went to spend the night at the victim's home. Schultz and the victim's older brother have been friends since 6th grade.

Sheriff's deputies were called to the victim's house at about 10 a.m. Sunday but the boy's family had whisked him to the hospital before authorities arrived. The boy was pronounced dead at the hospital.

Schultz was arrested about five hours later when he went to Kaiser Antioch Medical Center to be treated for slash wounds. It was there that a nurse recognized from social media that Schultz was wanted by the authorities and called police. Schultz told the paper he accidentally cut his right wrist while stabbing the boy. Schultz showed the Times reporter his fresh stitches.

The paper said that Schultz spoke calmly about the incident until he was asked if he felt remorse.

"I wish that I hadn't. I think about what if that was my little brother," Shultz said sobbing, as he referred to his 8-year-old brother. "In that sense, I do feel bad. I do have remorse for what I did ... But there's a reason for everything that happens."

Contra Costa County Sheriff's spokesman Jimmy Lee said deputies were dispatched to the Schultz family home in Discovery Bay on Saturday after Schultz's family called with concerns about his mental health. Lee said deputies determined that Schultz didn't require an involuntary mental health commitment, but he agreed to go to the hospital voluntarily by ambulance for evaluation and treatment.

County spokeswoman Kate Fowlie said privacy laws prohibit officials from discussing whether Schultz sought treatment.

"In general, if a person comes into our hospital for psychiatric evaluation, a mental status examination is conducted and if indicated, intervention is provided," Fowlie said in a prepared statement. "In circumstances where a person does not meet the criteria for a psychiatric hold, they are referred for follow-up care and other services."

The Schultz family couldn't be reached for comment.