Changing our mind

[Franz]

I know, most members of the forum believe that Lizzie did.

PossumPie suggested to me one day to change my mind, to consider the case from another point of view. Here I invite all the members of the forum to change for a moment their mind and consider the case in a different way. Let's suppose (just for a moment) that the killer was an intruder (it's possible), and everyone make a theory to explain the case, giving (at least) possible conjectures to, among others, these two crucial points:
1. When, from where and how did the intruder enter into the house;
2. The note story.

I am pretty sure that if you do this exercise, you will find that this would not be a easy task.