Miles Bench has already twice been determined competent to stand trial for the murder of 16-year-old Braylee Henry.
It's expected that on June 6, a determination will be made as to whether a third competency exam should be ordered.
Police say in June 2012, Bench attacked and killed Braylee at the store where he worked in Velma, east of Duncan.
Officers found blood in the store room.
A psychologist who had determined Bench was competent last June later changed her mind and defense attorneys asked that a jury determine his competency.
They found he was competent to stand trial.
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