This is a fun concept!
It could do with some locally run LLM I think, to reduce the stiffness of the conversation (no idea how realistic is something like that technically).
I managed to get two confessions, but it felt very chaotic.
The first guy confested right away after being asked "why he's here?",
the second randomly started describing the murder after I asked him "why he's gambling?" irrc.
I enjoyed the humorous bits too.
PS. I can't even image how the name Grzegorz will be prounounced in English once the officer Pulaski appears.