I'm looking for some more concrete information and as we some very competent information hunters here, notably Phillb and MrZhivago, maybe I shall be in luck.
I want to have a clear picture of the interior layout of the building in which the flat is situated and, preferably, of the flat itself. Obviously the house was once a single residence with the servants' quarters in the basement, the main entrance where it still is, and perhaps a tradesmens' entrance to the rear. But I don't know, for instance, if the door carried off by the police now leads directly into Joanna's flat or into a passage also leading to the other basement flat. Obviously when the servants were in the basement they had an internal staircase leading up the main parts of the building - is that still there and accessible ? In other words, can another resident reach J + G's flat without going outside (and if not what modification has occurred to the original staircase ) ?
I'd also like some more information about Peter Stanley, who originally looked to me about the only normal bloke around there (but I am impressed by some of MrZhiv's data). Is he another batchelor ? What is the source for his being a Clifton College shoting instructor ?
While I'm here, two further thoughts :
1. If Joanna texts an old acquaintance whom she hasn't seen for a long time and fails to raise a reply, she is unlikely to stop there, whether she is hoping for a fling or just company. After getting home, she would call others, until she struck gold. Perhaps she did and we haven't yet been told. Or perhaps she was interrupted before she could do so.
2. Given the big deal made by the police about the delays caused by the frozen state of the body, I wonder if the body might have been provisionally stored in a freezer. Granted the outdoor temperatures were most of the time freezing, but a freezer would produce a much more lasting effect and it is a fairly discreet place in which to keep an unwanted corpse.