Die Twice

Die Twice--two gripping Dennis Milne mysteries in one from Simon Kernick.
The Murder Exchange

When ex-mercenary Max Iversson agreed to provide security for nightclub owner Roy Fowler, he never expected a bloodbath. Three men have been shot, the briefcase Iversson was guarding is empty…and now he wants to know why. So begins a dangerous hunt for answers that will take him into direct conflict with Detective Sergeant John Gallan, who is investigating the mysterious death of one of Fowler's doormen, and toward a confrontation that neither is likely to escape unscathed.
The Business of Dying

Cynical and jaded, Detective Sergeant Dennis Milne earns money on the side by doing what he does best: punishing the bad guys. But this time he's been duped and instead of blowing away drug dealers, he kills three innocent men, setting off a war of morality that could leave him broken, or worse…dead.