From Amazon US:
Review
“Fresh, original and a wonderful read. I loved it.”—Charlaine Harris

“Midnight Riot is what would happen if Harry Potter grew up and joined the Fuzz. It is a hilarious, keenly imagined caper.”—Diana Gabaldon

“Filled with detail and imagination . . . Aaronovitch is a name to watch.”—Peter F. Hamilton

“The perfect blend of CSI and Harry Potter.” --io9.com

“Aaronovitch has created a fun and funny character in Grant, who displays wit more than snark (a welcome attitude) and shows he can think on his feet. . . . It's a great start to what will hopefully be a long series of adventures.”--SFrevu.com

From AmazonUK:
My name is Peter Grant and until January I was just probationary constable in that mighty army for justice known to all right-thinking people as the Metropolitan Police Service (and as the Filth to everybody else). My only concerns in life were how to avoid a transfer to the Case Progression Unit - we do paperwork so real coppers don't have to - and finding a way to climb into the panties of the outrageously perky WPC Leslie May. Then one night, in pursuance of a murder inquiry, I tried to take a witness statement from someone who was dead but disturbingly voluable, and that brought me to the attention of Inspector Nightingale, the last wizard in England.

Now I'm a Detective Constable and a trainee wizard, the first apprentice in fifty years, and my world has become somewhat more complicated: nests of vampires in Purley, negotiating a truce between the warring god and goddess of the Thames, and digging up graves in Covent Garden ... and there's something festering at the heart of the city I love, a malicious vengeful spirit that takes ordinary Londoners and twists them into grotesque mannequins to act out its drama of violence and despair.

The spirit of riot and rebellion has awakened in the city, and it's falling to me to bring order out of chaos - or die trying.

From GoodReads:
Probationary Constable Peter Grant dreams of being a detective in London's Metropolitan Police. Too bad his superior plans to assign him to the Case Progression Unit, where the biggest threat he'll face is a paper cut. But Peter's prospects change in the aftermath of a puzzling murder, when he gains exclusive information from an eyewitness who happens to be a ghost. Peter's ability to speak with the lingering dead brings him to the attention of Detective Chief Inspector Thomas Nightingale, who investigates crimes involving magic and other manifestations of the uncanny. Now, as a wave of brutal and bizarre murders engulfs the city, Peter is plunged into a world where gods and goddesses mingle with mortals and long-dead evil is making a comeback on a rising tide of magic.