Are there any references in statements to the deadlock being applied on the front door or was it as I suspect not seen as necessary as long as it was 'on the snib'?
Since Gerry and Kate left by the back door, The front door wouldn't have been locked by a key (Deadlocked)
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Despite what he said in his previous statements, he states now and with certainty, that he left with KATE through the back door which he consequently closed but did not lock, given that that is only possible from the inside. Concerning the front door, although he is certain that it was closed, it is unlikely that it was locked, because they left through the back door.
http://themaddiecasefiles.com/post524.html#p524It seems that one Security minded, witness did double lock(deadlock) their own door, but left the key under the door mat, because they were only issued with one key.