There are some parallels which can be drawn with the murder mystery genre. First of all, an inspector arrives to question the Birling household with regard to the death of a young woman. What is strange, however, is that the death is not a murder, but a suicide. The audience are therefore being led to deduce not who killed the girl, but whose actions made her so desperate to take her own life. The Birlings (and Gerald) are being interrogated to establish moral, not criminal responsibility.
Each character’s involvement with the young woman Eva Smith/Daisy Renton is revealed in turn, and each character’s connection provides a piece of the puzzle to the destructive nature of the relationship they had with the poor girl.
The purpose of the Inspector’s investigation here, however, is to establish collective guilt amongst the characters, rather than reveal individual responsibility-
We don’t live alone. We are members of one body. We are responsible for each other.