The link to photography

I just came across this thread and spent time reading through as many posts as I have time for. I recall at the time this was in the news I had a strong suspicion the man was involved in photography. There was the smell of "vinegar", the opportunity it gave somebody to work at all hours and be out of sight, the fastidiousness (based on photo lab technicians I've known) the tripod of course, and other details I don't recall now.

I'm sure this was pursued by police. If anyone has time to update me on whether any conclusion has been reached on that possibility.