-Ava escapes from the Asssasin and we don't know where either of them is when John is later murdered.
-Kristina takes off from her mother's house and goes to get the gun from Sonny but we don't see where she goes.
-Sonny nd Jason aren't seen at all that day so we don't know where they are or what they're doing. There's no agreement to meet at the Q mansion.
- Carly isn't seen until after the murder when she shows up at the Quartermaines late.
6 suspects who can't account for their whereabouts at the time of the murder. In the end they could easily just have it be the assassin that double crosses John after Ava escapes.