A serial killer may be stalking 1939 Berlin in Scarrow’s Blackout (Kensington, Mar.).

How does your book differ from those of authors such as Philip Kerr, who have also set whodunits in Nazi Germany?

I was aware of Kerr’s books and started reading one sometime before I decided to write Blackout. However, I felt I wanted to distance my reader from the protagonist and so avoided Kerr’s first-person approach. Nazi Germany was a place of facades where it was a very difficult thing to do to get under someone else’s skin. Therefore, a third-person narrative seemed most appropriate.

Why give your lead, Horst Schenke, a racing car background before he became a police inspector?

I’ve mentioned that Nazi Germany was a culture of facades. By making Schenke a celebrity, I aim to underscore that perception. It’s a world that injured him, and that he’s left behind to pursue his police career. However, his past, like anyone’s, follows him, and therefore his celebrity status amplifies that sense of being different from the way the world perceives you.

How did you approach crafting a narrative in which an honest cop tries to tackle “routine” crime under a criminal regime?

There’s always crime. And there’s always a semblance of the law which affects to uphold what the people consider to be a systematic application of the principle of justice. In a corrupt system, a good police officer is one who attempts to find a way to serve justice no matter how far the corrupt regime he serves attempts to drag the law in the opposite direction. In a way, Schenke’s predicament prefigures the Nuremberg defence: in the end it is not enough to obey orders—a servant of the state must ultimately place higher morality above higher authority.

What surprised you the most as you researched policing under the Nazis?

How much guarded contempt there was for the political arrivistes in the police force. A surprising number of senior police officers managed to resist pressure to join the party and/or accept an SS rank. Many saw themselves as professionals and were proud of their expertise. At the risk of drawing attention to contemporary resonances, I find it tragic that expertise and the authority of knowledge carries far less weight than it should in an era of cheap populist politics.