The site, on a greenbelt in downtown Boise, also is one of the few places in the world where the Universal Declaration of Human Rights is carved in stone.

Police are investigating but have made no arrests in the felony vandalism, discovered Tuesday by maintenance crews at the Wassmuth Center for Human Rights. The center is named for the late Bill Wassmuth, a former Catholic priest who is legendary in civil rights circles for his fight against racism.

Steven Goldstein, executive director of the Anne Frank Center for Mutual Respect in New York, called the vandalism an “act of unfathomable evil.”

“This act … demonstrates how we, as a society, have not yet reached the world of Anne Frank's dreams,” Goldstein said in a statement. “That's why our organization now focuses so strongly on contemporary injustice.”

“It is on us, or Aleynu as we say in Hebrew, to take a stand for goodness in today's world just as Anne asked all of us to do in her diary,” Goldstein said. “Never forget and never again, so help us God.”

Dan Prinzing, executive director of the Wassmuth Center, said he wouldn’t repeat the anti-Semitic graffiti scrawled on list of donors “because it was so offensive,” the Idaho Statesman reported in today’s editions.

On another marble tablet, containing the Universal Declaration of Human Rights, other graffiti “contained a racial slur and a message declaring black people aren’t human,” the newspaper reported.

The graffiti was written with a red permanent marker, and its ink saturated the stone. A removal process also damaged ink on the tablets letters, where shallow engraving can’t be repaired. Replacing the tablets will cost $20,000, and is expected to involve a special fund-raiser, Prinzing said.

The memorial commemorates Anne Frank, a Jewish girl forced into hiding during the Holocaust whose dairy of the experience became world-famous.

In 1995, a traveling Anne Frank exhibit drew in tens of thousands of visitors to Boise, leading to a grassroots campaign for the permanent memorial.

With support from community leaders, human rights activists and private individuals from throughout Idaho and elsewhere, the memorial was dedicated in 2002. It has since been visited by hundreds of thousands of visitors and students, seeking to better understand today’s human rights challenges.

The memorial includes a life-sized bronze statue of Anne Frank, peering out a window. With water features and outdoor landscaping, the memorial’s walls in the education park contain quotations from more than 60 humanitarian leaders.

The memorial also includes the Universal Declaration of Human Rights, adopted in December 1949 by the United Nations.

Prinzing said the graffiti, now removed, won’t blunt the memorial’s message of human dignity.

“They may try to get at the words that are carved in the stone, but they will never get at the intent and that just emboldens our mission and our work even further,” he said.