If it were not for Bernie Harrison's identity as a Member of Parliament being exposed at the last moment, this case would have been a sure conviction.
However, precisely because of this identity as a Member of Parliament, the case had escalated from a criminal matter to a political incident.
If Bernie truly were the murderer as the evidence suggested, it would be one thing, but if he were not, then Scotland Yard would inevitably find themselves under collective scrutiny by the MPs.
After all, Mr. Harrison was one of their own, and as the MPs saw it, if Scotland Yard could arrest Bernie today, they could just as easily arrest them tomorrow. This was not something that could be resolved by claiming a mere work error, as this represented Scotland Yard challenging the ultimate limit of parliamentary politics.