Edgy revelations and revealing first-hand accounts, including the inspirations for popular TV dramas as diverse as The Wire, The Sopranos and Life on Mars. Terrorists, criminal gangs, drug-dealing lawyers, solitary psychos and suspected serial killers all feature as the intended targets in these cops' tales.

Using fake identities and complex back-stories, dependent on teamwork to keep one step away from exposure, torture and death, the subjects of this book describe in vivid detail what it is like to cultivate contacts and gather evidence in major prosecutions: in the UK, Northern Ireland, the USA and around the world.