What night ? He said it was his and he used to use it to gain access into WHF through the bathroom window.
No, he didn't.
Bamber and his defence admitted that he had made marks to the bathroom/loo window and had been made with a thin blade. Bamber claimed they were made after the murders, so the only thing that's questioned was the date. they don't or I can't find where they deny using the hacksaw blade or I can't find where he admits using it?
It was the defence case, revealed for the first time at trial, that the appellant made those marks following his release after Police interview on or about 16 September upon his return from London having forgotten his keys
it is possible he did it on purpose to create the excuse that such could have been after the murders.