See Teen Charged With Killing Girl, 8, Showing Off Yo-Yo Tricks to Kids

Adrian Gonzalez, the 15-year-old boy accused of strangling his eight-year-old neighbor, Madyson Middleton and tossing her body into a dumpster, has appeared in court for the first time.

The teenager is accused of luring his neighbor, who was known as "Maddy," to his apartment at an artists' colony where they both lived in Santa Cruz, California on Sunday.

Read: 8-Year-Old's Final Moments Before Teen Neighbor Allegedly Lured Her to Her Death

Gonzalez is known in the neighborhood as a yo-yo master. He uploaded video doing tricks with his favorite yo-yo. Investigators say he was "obsessive" about the toy.

On the day of the murder, he posted a video from the song “Mad World.” He wrote down the songs dark lyrics: "The Dreams In Which I'm Dying Are The Best I've Ever Had.”

At a candle-light vigil on Wednesday night for Maddy, classmates of the accused were stunned by news of his arrest.

One classmate told reporters: "I would have never expected someone like him to do that. He was so nice. He didn't seem like he had problems or anything." 

Read: 72-Year-Old Veteran Walked into Army Office with Gun to 'Keep Staff on Their Toes'

Gonzalez is being charged as an adult with sexually assaulting and murdering the child.

Maddy was last seen alive on surveillance camera enjoying the razor scooter she had been given that day. She was allegedly tied up, raped and strangled, according to the prosecutors charging documents. Her body was carried downstairs and hidden in the recycling bin.

If convicted, Gonzalez could face life in prison.

Watch Below: Last Video of 8-Year-Old Before Neighbor Allegedly Lured Her to Her Death