The one thing that we all assume is that Mum & Dad were asleep. They were visiting friends in the city and I think that it said in one of the reports that they weren't expect back till the next day. So after everyone has left the party JD comes back to spend the rest of the night with CR ,as a caring boyfriend will do if your girlfriend was sick.
Mum & Dad come home find them in bed together, maybe they were asleep. Dad loses his Cool, neighbour hears the Domestic, man, women screaming. If it was you finding your daughter like that I think you would lose it.
Say dad grabs JD and drags him into the kitchen and starts to slap him around, JD sees the knives in the block and grabs one and goes bersek.
That would explain the cuts on JD because as the blood was getting on the knife it became slippery and his hand was sliding on to the blade. Dad drops to the floor and JD trys to do a runner, Mum confronts him and he takes to her and she goes down. CR comes out of the bedroom and goes hysterical, JD panics and takes the knife to her.
He has time to calm down and tries to make it look like a phycopath sex nutter did it.
He goes to the school, remember the alarm went off, he cleans up there, all schools have fantastic first aid rooms. He could easily hide the knife in the ceiling cavity in the school. He had enough time to clean up and calm down, then go home to wake up to a new day. Possible??
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