CASPER (WNE) — Dominique Antonio Richard Harris, accused in the killing of Dean Morgan Middle School schoolmate Bobby Maher, pleaded not guilty Wednesday to a charge of conspiracy to commit first degree murder.

It’s the latest development in one of the state’s most closely watched criminal proceedings, and comes five days after Harris’ alleged accomplice, Jarreth Joseflee Sabastian Plunkett, pleaded “not guilty by reason of mental illness.” 

Harris, born in 2008, is alleged to have facilitated the crime by slamming Bobby Maher, 14, to the ground and striking him in the face in the moments before he was stabbed in the parking lot of Casper’s Eastridge Mall, according to the police affidavit. 

The April 7 slaying made headlines around the globe, shook a community and set off calls for reform — all while bringing fresh attention to some of the damning realities of youth challenges in the Cowboy State, including its place as the state with the highest per-capita youth incarceration rate in the nation. 

During his arraignment at the Natrona County Courthouse in Casper, Harris also pleaded not guilty to aggravated assault and theft. 

The trial is set for Sept. 23.