The perpetrator, the weapon, the motive — even the season the crime was committed — remain a mystery. Maybe someone took a car key and scratched the words in a fit of hatred. Or maybe the person picked up a rock and, egged on by friends, wrote the worst thing he could think of.

"Upon his deeds not his ideas does God's favor rest on man," the plaque once read, before someone scratched through the word "God." The quote is attributed to Rabbi Eric Silver, but "Rabbi" has been crossed out as well, and at the bottom of the plaque the words "Jews suck" have been added.

Former Salt Lake planning director Stephen Goldsmith discovered the graffiti earlier this fall. He told his friend, lawyer Pat Shea, who contacted Judge Memorial Catholic High School, which erected the plaque in the mid-1980s as part of the Freedom Trail in City Creek Canyon.

On Monday morning, Bishop George H. Niederauer of the Catholic Diocese of Salt Lake City and 10 students from Judge Memorial trudged through the snow to the religious freedom site, one of several shrines to various freedoms erected by Salt Lake City public and private high schools two decades ago.

The students had hoped to replace the plaque, which has been removed, with a new one, but the plaque wasn't finished in time. It didn't matter though — the real lesson was about being a witness to what had happened.

Bishop Niederauer took the opportunity to share a lesson about speaking up against hatred. It's not enough not to make discriminatory remarks yourself, to not deface a plaque yourself, he told the students. We fail each other, he said, when we sit by when someone else tells a racist joke, when someone else scratches hateful words. Quoting English philosopher Edmund Burke, he noted that all that is required for evil to prevail is "for good people to do nothing."

Speaking up against hateful speech is like exercise, he told the students. "Other people can't exercise for us, or worship for us, or defend freedom for us." Perhaps the defacing was done in the dark, the bishop said. Now, "in the daylight, we're up here saying 'this will not do.' "

Later, walking back down the snowy path, seniors Tyson Dudley and Stephen Goddard wondered aloud why anyone would write something hateful about someone else's religion.

"Hate is something that comes from ignorance," their teacher, Kandie Brinkman, told them.

Brinkman teaches a social action class as part of the "Justice, Peace and Diversity" curriculum required of all Judge Memorial students before they graduate. In fact, she says, Judge Memorial is the only Catholic high school in the country that requires its students to take a class about diversity.

The plaque incident was also a good opportunity, Brinkman said, for students to realize that the fight against hatred is not new, that the students' questions and ideals are part of a "legacy of conscience" that began 20 years ago with the Freedom Trail shrines, and long before that as well. And it's important for them to realize that the fight isn't over, she said.

Because her students are idealistic, she said, "they think we've solved these problems" of racism and sexism and religious intolerance.

After their hike, the students joined Bishop Niederauer and lawyer Shea for lunch, where they talked about what Judge Memorial students could do to promote diversity and tolerance, how to speak up when someone else's beliefs have been ridiculed, how to speak up for their own beliefs.

Bishop Niederauer and the students tried to imagine who might have defaced the plaque. To show off, one student suggested. To be mean and hurtful, another said. Bishop Niederauer admitted that he immediately assumed the perpetrator was a "young guy," then added that they all need to be careful about their assumptions.

Maybe, the group suggested, the perpetrator was angry because he felt he had been hurt by someone. Maybe he was the victim of abuse. "In an awful way, it's the gift that keeps on giving," Bishop Niederauer said.

The free-ranging discussion touched on intelligent design, sexism, ethnic food and Utah's Mormon/"non-Mormon" divide. "The acid test is always going to be 'how do Catholics talk about LDS when only Catholics are in the room, and how do LDS talk about Catholics when only LDS are in the room," Bishop Niederauer said.

"It's easy to isolate yourselves into a comfort zone, with people just like you," Shea cautioned the students.

Brinkman said what she hopes to teach her students is to be advocates — "to get people with the power to speak up for those who don't."