Jane and Renata
The Motive: An obvious one: new-in-town Jane (Shailene Woodley) finds herself targeted by rich career woman Renata (Laura Dern) when Jane's son Ziggy is accused of assaulting Renata's daughter, Amabella. Renata is so livid that she actually threatens Ziggy, but given the mystery around Jane and her own mama-bear reaction, we'd say if it came down in a showdown between these two, it would be Jane as the assailant. Another reason to suspect Jane is that we see her handling her gun in a Chekhovian moment. There's also this: in the beginning of the pilot, one of the witnesses notes that if Madeline (Reese Witherspoon) hadn't fallen — the event that spurs Madeline and Jane to become friends — "nobody would have gotten killed." So does Madeline egg Jane on to kill Renata?