The Fourth of the Policeman Wizard series from Dr Who writer Ben Aaronovitch.
In ‘Broken Homes’ there are a series of deaths that seem like isolated cases, except PC Peter Grant recognises the vestigia (signature) of the evil (and arguably psychotic and certainly a very sick little muppet) wizard the Faceless Man. This lead to an unusual housing estate, a magic garden and a lot of coffee as Peter, Lesley and Toby investigate.
This is good, I like all his novels in this series so far, but it is not a good as the three before and often seems to be both meandering and rushed. Then I Facebooked my enjoyment of this book and a friend said “why are you reading those books? They are just a poor rip off of the best magical detective ever, Harry Dresden” and dammit she was right.
Though poor rip off is strong and a bit unfair. There is a lot to love in this series of books in their own right… BUT I would definitely say that Jim Butcher (The Dresden Files) is the creative designer and these books are the cheaper, more flimsy supermarket version, just different enough to be legal, though if I were Jim Butcher I would sue!
Still worth a read though as an ode to London alone they are great and, lets face it, you can never have too many kick arse wizard detectives!