A 12-year-old Michigan boy pleaded not guilty to a murder charge in juvenile court Tuesday after he fatally stabbed a 9-year-old while the two were playing on a playground Monday evening. 

The boy was ordered held until a preliminary hearing scheduled for August 13. He is designated as an adult in the juvenile court system, which would allow the boy, if convicted, to be sentenced as a juvenile and then as an adult once he turns 21, according to Chris Becker, Kent County Chief Assistant Prosecutor in Kent County, Mich. 

Authorities said they were still investigating what led to Monday evening's attack, which left 9-year-old Michael Conner Verkerke dead after the older boy stabbed him with a steak knife. Investigators said it didn't appear that the suspect and victim knew each other prior to the attack, which took place while the victim, his brother, his best friend, and the suspect were playing in Kenwood, near Grand Rapids. 

A neighbor of the suspect told WXMI-TV he was not surprised that the 12-year-old committed the act. 

"He seemed to have big eyes, you know what I’m saying," the neighbor told the station. "Like, you kind of felt like you wanted to watch your back."

Witnesses said the suspect went to a nearby mobile home and called 911 to report the attack and turn himself in. 

"The only time he raised his voice was when the police came," homeowner Glen Stacy told the Grand Rapids Press.

When officers arrived at the mobile home park, they first went to aid the stabbing victim, but the older boy wanted the officers to pick him up and yelled, "Hello, I'm right here. You're going the wrong way," Stacy said.

The Associated Press contributed to this report. 

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