William Ryan's The Constant Soldier takes forensic look at mass killing

Ordinary people turned from good citizens to eager murderers in Nazi Germany. How could this happen? Sue Leonard discovers how, from the author of a new novel.

WHAT makes a man capable of murder? What did it take to make former bank clerks and ex-policemen happy to work in German camps whose business was mass murder? It’s a question that has long fascinated the London-based writer, William Ryan.

And when he had finished his historical crime trilogy, set in the past in Russia, featuring the detective Captain Korolev, Ryan decided to research the matter further.