Mr Briggs' Hat has been compared with Kate Summerscale's The Suspicions of Mr Whicher, and this real life detective is mentioned as a contemporary of the book's policeman, Tanner, but it reminded me more of PD James's The Maul and The Pear Tree, the subject of which was the Ratcliffe Highway murders. This book takes place in an entirely different milieu, not the Georgian slums of Wapping, but the mid-Victorian bourgeois enclave of Hackney (yes, before it was gentrified, it was posh): a banker murdered on the train between Fenchurch Street and Chalk Farm.
Colquhoun has obviously, more than obviously, done her research. Every detail is meticulously referenced in the notes. Tanner can't wipe a handkerchief across his fevered brow without this being noted as having been reported in the Times, p7, 1st August 1864. Strange then, that there is an essential mix up between Hackney Central station (then just called Hackney) and Hackney Wick (also known as Victoria Park). Given that the murder takes place between Bow station and Hackney Wick, this is kind of a crucial detail. But Colquhoun has Briggs get on the train at Hackney Central and there is even a rather lovely Victorian drawing of Mare Street with Augustine Tower in the background. She also confuses Euston station with Euston Square (tube) station, which didn't exist at the time. She does use her research to provide period details to create atmosphere, but sometimes it comes over as rather purple-prosey.
There is much plus ca change: private train companies that put profit before safety, the police fail to follow leads that don't fit with the supposed version of events, witnesses are considered unreliable based on social status, the newspapers pre-judge the defendant before his trial, there's a draconian Home Sec, happy to send a possibly innocent man to his death, and other politicians use the case to further their own agendas.
The main crux, however, is did Muller kill Briggs it? This is the Victorian version of Making A Murderer. The evidence looks pretty water tight – until it doesn't. The detail and research sometimes slows up the book so you don't get any feeling of urgency or energy - I did wonder if Colquhoun should have novelised the story, rather than created a true crime book, but overall it's an enjoyable slice of Victorian history.