Factual error: Kyle says he has to log on before school. The next shot shows "Monday 8 days later." 8 days before is a Sunday. (00:04:45)
Factual error: Whenever the killer (always dressed in black with a balaclava disguising his/her identity) uses a knife, the blow invariably is an overhand strike. However, a knife in a downward thrust quite frequently simply skids off the overlapping ribcage of the victim.