Originally Posted by Reality Sucks:
“yes, but if you were accuised of muredr and were innocent, wouldn't you be wondering who actually did do it?”
Well yes, somebody in their right mind that was thinking straight would bu Peter clearly isn't. He is either p++++d out of his skull (on some very rough moonshine in Prison) or going through withdrawal. All he can think about is alcohol and what a mess his life is - not why it's like that or what he can do about it. All he cares about is that next drink. That is the nature of addiction.
Plus, if he did think about it he'd discount Rob and Tracy because not only are they each others alibis but Deardre is backing them up. Why would she do that? The thing is, Deardre doesn't actually realise she is lying, she genuinely believes they were upstairs and probably hasn't told anybody (including poeter) that she didn't actually see them and that fact is crucial.
Yes, it was in their backyard but anybody can get into it from the alley at the back - there doesn't seem to be a lock on the gate. Or they could have just chucked it over the fence as they were fleeing the scene of the crime. It isn't conclusive proof that it was a resident of the house - it is circumstantial but because there is a fair amount of circumstantial evidence against Peter (including the best motive) the Police have run with it.