I'm not sure that a recent third author writing crime fiction based in India constitutes a new trend, but after Tarquin Hall and Vasim Khan, it is the turn of yet another Brit, Abir Mukherjee, to take up the genre. Mukherjee, however, sets his new procedural A Rising Man, in the past - in Calcutta, where, in 1919, there is already a insurrectionist mood, and the imperial interlopers are feeling nervy. Into this arrives a veteran of the Great War - Wyndham - who, in true detective style, has a tragic past and an addiction problem. As he is new to India, he needs a big info dump, which is of course Mukherjee's way of educating the reader.
There seems to be a requirement these days to have a likeable protagonist, so Wyndham is suitably anti-imperialist, unsexist and unracist. Your typical modern liberal, in other words. To show him off as even more likeable, his deputy (another Brit) is a bigot; to demonstrate his manliness, his sergeant Banerjee is a nerd; to prove he is progressive, his love interests are all intelligent women.
Then there are the crimes: a murder of a British administrator, and a robbery and murder on a mail train. Naturally, there will be a connection and it will be unearthed by Wyndham, who has to battle not only his personal demons but also colleagues and rivals from other departments of the security establishment. As police procedurals go, this book ticks all the requisite points: a shifty witness at the crime site, autopsies and nauseous onlookers, bursts of derring-do, a twist or two in the tale. The novel strives to be bigger than that, with expository analyses of Bengali socio-economics and effete intellectuality. There are bitter outbursts about the iniquity of foreign occupation, the rootlessness of mixed-race people. There are long lectures by various characters. And you can't have Calcutta without a description of its imperial splendour and native squalour.
Soon after reading this book, I came across Barbara Cleverly's older series of historical crime fiction. This has Joe Sandilands, another decorated soldier and Scotland Yard detective, who arrives in India on some sort of lecture tour, but can't wait to leave. In the first book, titled The Last Kashmiri Rose, just as he is making tracks to leg it from India, he's dragged into investigating a death of a British woman at an outpost not far from Calcutta. Proceeding there, he soon comes to realise that this death is only the latest of a set. Once again, you have a likeable protagonist - somewhat naive, even - who is not swayed by imperial pretensions of superiority. You have a hyper-efficient Indian subaltern, a very clever Englishwoman who Sandilands is suddenly in love with (and who also serves to educate both him and the reader on the mores and attitudes of the Raj and the natives), and various politicking Brits and suspicious babus. While Cleverly appears to have researched the milieu and era quite a bit, there are some jarring notes to an Indian ear: dubious mythologies and references to deities, some expressions that are quite unlikely to have been used at the time, and peculiar Indian names. The book was a New York Times Notable Book of the Year in 2002; it must have been a rather slow year for historical fiction for that paper.