@Blonderabbit as you visited the alleyway can I ask you in your opinion was it wide enough someone riding a bicycle, moped or motorcycle directly to the rear entrance of Claudia's property.
Also did you notice how many if any properties had rear security lights.
Was your visit conducted in daylight, darkness or both?
I know the alleyway has been improved since the investigation but when you visited what in particular were you looking at/for and what notes did you make on that particular location.