The 17-year-old Hilliard Davidson High School student charged with conspiracy to commit murder pleaded not guilty during his Oct. 2 arraignment in the Franklin County Court of Common Pleas.

John Leonard Staley III, a northwest Columbus resident, is accused of plotting a mass shooting at Davidson. He will be tried as an adult.

A $250,000 cash or surety bond and a $20,000 recognizance bond were set during the arraignment, according to Franklin County Prosecutor Ron O'Brien.

The case will be assigned to a trial judge, O'Brien said.

A Franklin County grand jury indicted Staley on Sept. 28 for conspiracy to commit murder, a first-degree felony.

O'Brien said the indictment belies the scope of the conspiracy Staley is accused of perpetrating.

"Apart from talking about a school shooting, Staley took substantial steps to carry out a conspiracy to commit a mass shooting in the cafeteria at Hilliard Davidson last fall (and) he will now be tried as an adult," O'Brien said.

Staley was arrested in October 2016 and charged with a delinquency count of conspiracy to commit murder after a student contacted a school resource officer at Davidson and told the officer Staley was overheard on a school bus discussing the plot, he said.

Staley created diagrams of locations in the school building and attempted to recruit other students, O'Brien said.

The grand-jury indictment refers to the other students by using initials.

The indictment specifies "substantial overt acts in furtherance of the conspiracy" as providing a map or diagram to a specific individual and soliciting other individuals to commit murder.

The indictment followed a Sept. 6 hearing at which Franklin County juvenile court Judge Terri Jamison ordered Staley tried as an adult and held in the juvenile detention center on a $250,000 bond.

Stephen Palmer, an attorney representing Staley, told ThisWeek on Sept. 19 that a not-guilty plea would be entered during the arraignment.

Palmer said psychologists and other experts concluded that Staley should not be tried as an adult but "the judge thought otherwise."