In Broad Daylight: The Secret Procedures behind the Holocaust by Bullets  By Patrick Desbois (Arcade, 281 pp. $25.99)

Father Patrick Desbois’s first book, The Holocaust by Bullets: A Priest’s Journey to Uncover the Truth Behind the Murder of 1.5 Million Jews, a National Jewish Book Award winner, documented the murder of 1.5 million Jews in Ukraine during the Shoah. In Broad Daylight continues to follow that trail, with Desbois demonstrating that the mass killings of Jews in Ukraine, Belarus, Russia, Poland and Moldova, following the Nazi invasion in June 1941, were not random. The Einsatzgruppen (mobile killing units) went from village to village recruiting the native population to help kill the Jews who lived among them. Some recruits eagerly murdered their Jewish neighbors to collect the spoils; others were forced to build the infrastructure that made the killings more efficient. The locals cooked and fed the troops, dug the pits and then rounded up and marched the Jews to the prepared graves. After the Einsatzgruppen shot the Jewish victims, the locals thrust them—those who were dead and those still living—into the mass grave.

The evidence of the orchestrated murders that occurred between 1941 and 1944 are documented by Yahad-In Unum (the name is a combination of Hebrew and Latin, meaning Together in One), the French research organization founded by Desbois in 2004. Researchers have confirmed 2,300 mass killing sites and about 5,700 witnesses have given videotaped testimonies.

For Desbois, the requisitioned villagers were “the hidden face of the Einsatzgruppen, who could engage in the killing operations thanks to an on-site population that was always there to do their dirty work.” The availability of labor, food and materials allowed the Germans to engage immediately in their genocidal crimes and depart the same evening for their next killing operation.

Jack Fischel is author of The Holocaust and The Historical Dictionary of the Holocaust.