Umineko no Naku Koro ni Shi - Forgery of the Purple Logic - Vol. 2 Ch. 9

[MangaDex]

 

[gamma2015]

my bet's on the doctor

 

[NikoLazuli]

rosa mentions purple lie "the warehouse is locked from outside, so its impossible to open it from inside"
Beatrice states in red that "the keys can lock and unlock each door from the inside".
however if rosa is the culprit that leaves the problem of how she was always with maria.

 

[Near]

I think Beato's reds applies to rooms in the houses not the warehouse. they won't lock Natsuhi and Jessica in a warehouse if they can just unlock it from the inside and leave...