Cardinal Francis George, President of the U.S. Conference of Catholic Bishops, has decried the “appalling” shooting at the Holocaust Memorial Museum in Washington, D.C. as a “deplorable act of violence.”

On Wednesday an 88-year-old man named James W. von Brunn reportedly opened fire on the U.S. Holocaust Museum in Washington, D.C.

Security guards returned fire and critically injured von Brunn but not before he fatally wounded 39-year-old security guard Stephen Tyrone Johns.

In 1981 von Brunn was charged with trying to kidnap members of the Federal Reserve Board and was in prison until 1989, the Washington Post reports.

A Holocaust denier, von Brunn authored an essay for an atheist website in which he asserted that Christianity was used to destroy the Roman Empire and the Holocaust was being used to destroy “Western Civilization.” He accused the Apostle Paul of using a “Big Lie” technique to create Christianity and insisted this technique was also used to create “the Holocaust religion.”

“Christianity and the Holocaust are hoaxes,” he claimed in his essay.

In a Thursday statement reacting to the “appalling” shooting, Cardinal George, who is president of the U.S. Catholic Bishops' Conference, characterized the June 10 incident as a violation of a “hallowed space” in the U.S. capital.

“By preserving the memory of the six million Jews who died in the Shoah, the Museum speaks to the consciences of all who pass through its doors and hear the powerful stories of the innocent men, women and children who lost their lives at the hands of a criminal regime.”

Cardinal George said that the millions of visitors to the museum learn the dangers of “unchecked hatred” and learn the need to prevent genocide.

“This tragic incident only serves to reinforce the need for continued education throughout society against bias of every kind, but most especially racial and religious prejudice,” he said.

“On behalf of the Catholic Bishops of the United States I offer prayerful condolences to the family of Officer Stephen Tyrone Johns, who died in the line of duty, and to the staff of the Museum who endured this appalling act of violence.”

Reiterating the Catholic bishops’ commitment to the protection of “the sacredness of all human life” and the promotion of human dignity and interreligious peace, Cardinal George cited Pope Benedict XVI’s comments at a January 2009 General Audience:

“May the Shoah be a warning for all against forgetfulness, denial or reductionism, because violence committed against one single human being is violence against all.”