Among the many things the Rev. Patrick Desbois wants the world to remember about the Holocaust is this: It was a crime. Because it was a crime, there must be evidence. And that evidence must be collected.

The French Catholic priest has made it his mission to do that in the 20th century’s biggest mass homicide case. He specializes in documenting the Nazi-organized shooting of Jews in the former Soviet Union and other parts of Eastern Europe. There are still bullet cartridges in the ground near mass graves. There are still wedding rings and other bits of jewelry to be discovered near the remains of victims. There are still eyewitnesses. “Holocaust by bullets,” Desbois calls it, in a book that he wrote in 2008 and a class he teaches as an adjunct professor at Georgetown University.

“The Holocaust was not a tsunami. It was a crime. It was a personal crime,” Desbois said Wednesday in a telephone interview. “There was no shooting without responsibility. We want to establish the criminal responsibility of the Holocaust.”

Desbois’s forensic work on the Holocaust is at the heart of a gift that Georgetown just announced, $10 million from Miami philanthropists Norman and Irma Braman, to support research into the Nazi-led extermination of 6 million Jews in during World War II.

In all probability, there are very few endowed chairs in academia for Holocaust grave hunters. But Desbois, 60, is about to hold a chair created through the Braman gift: the Braman Endowed Professorship of the Practice of the Forensic Study of the Holocaust.

The gift is part of an expansion of scholarship of Jewish civilization at the elite Jesuit university in the nation’s capital.

The approach of Desbois is multidisciplinary, using historical, anthropological, psychological and legal evidence to show the toll of mobile killing squads in Ukraine and elsewhere under the regime of Nazi terror. He also is relentless in pursuing interviews of eyewitnesses while they are still alive.

“We are in a race against time,” he said. “Witnesses are getting old. We’re trying to accelerate the research.”

Desbois said that “Holocaust by Bullets” is unfortunately the model for mass killings today. “Thus, the lessons to be learned are practical, and the details need to be exposed for all to see and understand.”

Desbois added: “The assassins never imagined that 70 years later, men and women motivated by a quest for the truth would interview eyewitnesses to the killings of Jews. To all those who commit genocide we say: sooner or later, wherever the mass-murder of humans has taken place, someone will return. Norman and Irma Braman’s gift will ensure that this happens.”

A native of a small town in Burgundy, France, Desbois said he became interested in the Holocaust as he traced the wartime path of his grandfather, who had been held as a prisoner of war in the Rava-Ruska camp in Eastern Europe. He later learned from eyewitnesses that Rava-Ruska had been the site of a mass killing. That spurred him to start asking more questions.

In 2004, Desbois founded Yahad-In Unum — taking its name from Hebrew and Latin words that mean “together in one.” That organization, based in Paris, where he lives, is dedicated to identifying and documenting sites of mass executions during World War II. To date, according to a news release, it has identified 1,900 mass killing sites and interviewed more than 4,800 eyewitnesses in Ukraine, Russia, Belarus, Moldova, Lithuania, Romania, Macedonia and Poland.

It is estimated that Nazi units called “Einsatzgruppen” and related mobile killing units murdered more than 1 million Jews. Many more were shot and killed by various other groups during World War II, Desbois and his team believe. The Jewish death toll of the Holocaust, including victims of Auschwitz and other death camps, was 6 million.

Desbois is director of the Episcopal Committee for Relations with Judaism, connected to the French Conference of Bishops, and has served as a consultant to the Vatican on relations with Judaism.

He was recruited to Georgetown in 2013 by the Rev. Dennis McManus, another faculty member, who is a liaison to the Jewish community for the U.S. Conference of Catholic Bishops. The two teach the Holocaust by Bullets course together. By all accounts, it is wildly popular. In March several students plan to go with Desbois to Eastern Europe for more field research.

He said he is moved that students are drawn to his class. Desbois said students tell him: “You know what? We realize there are mass killings everywhere in the world. We want to study what happened during the Holocaust to know to fight for a country without mass violence.”