What is the author's style in Into That Darkness: An Examination of Conscience by Gitta Sereny?

The author addresses the question of responsibility. Accountability is important on account of what happens before, during and after the war and also what occurs for people when assessing war crimes. The subject Franz Strangl is held responsible as a war criminal for his leadership at an extermination camp. He is convicted of having killed 900,000 Jewish people at this camp, over a 12 month period, during 2 tours of duty.