SHEBOYGAN, Wis. - A 13-year-old Sheboygan boy accused of killing and robbing his great grandmother has been ordered to undergo a competency exam.

A judge granted the defense's request for the exam on Monday.

Antonio Barbeau and his 13-year-old friend Nathan Paape allegedly used a hatchet and a hammer to kill Barbara Olson at her Sheboygan Falls home last month before stealing money, jewelry and a car. The victim's daughter discovered her body in the garage two days later.

Investigators say the boys used the money to buy drugs and pizza.

Both teens have been certified to stand trial as adults.

Monday's ruling means Barbeau will be evaluated by a court-appointed mental health professional, who will determine whether the teenager is competent to stand trial, or would be if provided appropriate medication.

A competency hearing has been scheduled for Nov. 2 following completion of the examination.

Barbeau's attorney George Limbeck filed a motion Friday seeking the evaluation, arguing that Barbeau is unable to understand the legal concepts needed to assist in both his defense and for a reverse waiver hearing that will determine whether the case will be sent to juvenile court.

Limbeck said in court that a combination of Barbeau's age and a brain injury he sustained in an earlier accident may be impairing his mental competency.

District Attorney Joe DeCecco opposed the motion, arguing that there wasn't sufficient evidence that an examination was needed and acknowledged that while Barbeau had previously suffered a concussion, medical records showed no evidence of serious brain trauma that would impair his competency.