Youl notice that when Lee and Mark go out to fix the fences he turns the fence on to try and kill you. He says he heard mark yell to turn it on but mark only yells after he turns it on.
When you Go out to hunt bandits with danny you find the CamCorder and dannys like Oh crap what have you got there. And when you say its not working hes like Oh Phew. (meaning that hes afraid youl find out they are killers)
The only reason you and danny go out hunting for bandits is to leave INJURED Mark alone with brenda and Andy so they can Start to kill him.
Also When brendas on the porch and you go up to her shes like "dinners ready soon" then her face goes all DEMONIC, it looks just like a graphical glitch but you can tell shes an evil mofo