CHATTANOOGA, Tenn. - The 24-year-old driver in a school bus crash that killed six children last month in Tennessee is appearing in court.

Johnthony Walker's preliminary hearing will take place Thursday morning in Hamilton County court. He's charged with five counts of vehicular homicide, reckless driving and reckless endangerment. Police say a sixth charge of vehicular homicide will be added.

Thursday's hearing will determine whether Walker's case will head to a grand jury.

Federal authorities say Walker left the designated bus route Nov. 21 when he wrecked on a curvy road while carrying 37 children. Authorities suspect Walker was speeding.

Walker's attorney, Amanda Dunn, has said she expects him to plead not guilty if he's indicted.