Police say California boy , 12 , arrested on suspicion of fatally stabbing sister , Fowler , 8 . Before Leila 's death , the boy 's middle school in Valley Springs suspended him for five days after he brought a small pocketknife to school , according to one of the boy 's classmates . Boy was arrested this year for bringing small pocketknife to school , police sources say . Authorities have n't said what kind of knife was used in boy 's death .
Police say California boy , 12 , arrested on suspicion of fatally stabbing sister , Fowler , 8 . Boy was arrested this year for bringing small pocketknife to school , police sources say . Authorities have n't said what kind of knife was used in boy 's death .