I have completed 5 murder mysteries of this sort and this would rank as the worst: in others that I have done, information is provided and prompts are given (such as "ask Joe Bloggs where he was at lunchtime" or "when asked, tell Joe that you last spoke to Bill last night") to the characters to keep the discussion on track, but the conversation can flow freely. In this game, characters are following a script, which makes it much like a play read-through. The conclusion was somewhat of an anticlimax too.
My advice: buy a different game. The ones produced by BV Leisure (rather than Paul Lamond Games) are in my experience better thought through and more fun.