Sacre When I saw "the wall" on GN I just knew it would turn out to be someon on this thread 
I think Lauren is wrong, I don't think it was a Beale or that it happened in the Beale's house.
Emma had the "SOC" thing written down, with the (Beale's?) phone number before she found out who the actual killer was.... Then she had her penny dropping moment, looked at the Beale's house and said "it wasn't there".... Meaning she realised that it didn't happen at the Beale's house?
She didn't get rid of her original scribblings or tell anyone else then died.
Maybe Dean thought she was Lauren (matching suits?) followed her and tried to rape her but in ended up in a scuffle?