"Philip Kerr published 'March Violets,' his first Bernie Gunther novel, in 1989. The obsession with World War II and the Nazi regime was of course long-established, the subject of countless novels, memoirs and films. Mr. Kerr's originality was to write about prewar Berlin from the point of view of a German Nazi-skeptic, an ex-cop turned private detective. The book was an immediate success, and over the past 20 years Mr. Kerr has followed Gunther's career—in which he is drawn against his will into the Nazis' world—through the war, its immediate aftermath and to Argentina, which offered a refuge to so many Nazi criminals. If the novels set in the 1930s are the most compelling, this is because they remain the freshest, assuming that adjective may properly be applied to any depiction of Hitler's repulsive regime. But Mr. Kerr has set a fashion, and now Berlin Noir is a crowded place.… But Mr. Kerr has set a fashion, and now Berlin Noir is a crowded place."
Massie (the well known Scottish author and journalist) goes on to discuss the growing field of period crime fiction set against the backdrop of Nazi Germany and his theories about why today's readers are so drawn to the genre: http://online.wsj.com/article/SB10001424052748704013604576249412996836894.html