Colleges across the United States have become the stage for hate crime hoaxes that thrust the purported victim into the limelight and twist campuses into turmoil.

At San Francisco State, two black students reported racial epithets scrawled in their dorms. At Northwestern University in Illinois, a freshman told police that someone grabbed him from behind, held a knife to his neck and uttered an anti-Hispanic slur. At the College of New Jersey, the treasurer of a gay organization said someone sent threats on his life.

In each instance, police said, the alleged victims turned out to be the perpetrators.

Although such incidents occur everywhere, experts say college campuses can provide the perfect petri dish for cultivating a hoax: a community capable of rallying to correct a perceived injustice.

"A person who is a victim of a hate crime can probably expect to get almost universal sympathy on a college campus. Out in the world at large, that's not necessarily true," said Mark Potok, who has researched hate crime for the Southern Poverty Law Center in Montgomery, Ala.. "But on a college campus, you are very likely to get the support of the administration, the faculty and virtually all the students. It tends to put you in the limelight very quickly."

In March, classes were canceled at the Claremont Colleges in Southern California as students and faculty rallied in support of Kerri Dunn, a visiting professor of psychology whose car was vandalized and spray-painted with anti-Semitic slurs after a forum denouncing intolerance. A hate crime, Claremont police first said. But a week later, police said they thought Dunn did it.

Dunn, who has been charged with two felony counts of insurance fraud and one misdemeanor count of filing a false police report, has denied any wrongdoing.

Campus hoaxers are usually students, experts said.

"A professor is part of the power structure," said Brian Levin, director of the Center for the Study of Hate and Extremism at California State University at San Bernardino. "A professor also has much more to lose."

Motivation varies. Some believe their cause is so worthy that any means of getting attention is justified. For others, it's revenge. Still others are mentally ill, experts say.

In several cases, the perpetrator was attempting to divert attention from a personal problem or cover a mistake.

Sometimes hoaxes are staged for what seem like relatively trivial reasons. A San Francisco State student, Allison Jackson, now 21, reported to police in September that someone wrote obscenities on a dorm room door.

Later in the month, after being confronted with a handwriting analysis, Jackson said she faked the incident, according to a campus police report, because she wanted "a roommate change" and housing officials were taking too long to respond.

"I was given the advice that in order for the roommate move to be taken seriously, things needed to occur," Jackson said, according to the report. She wrote on the door, she told police, "because that was the drastic event that was going to get us moved."

In another San Francisco State incident last September, a black student named Leah Miller, now 19, admitted to scratching part of a racial epithet on a dorm room door and to writing herself a note with the same epithet. She apologized to police and said she wanted to be accepted by other students and draw attention to what she regarded as racial issues on campus.

"I tried to be part of something," Miller told police.

Another explanation for hoaxes? Immaturity, said Nathaniel Snow, a former student leader at Miami University in Ohio. He offers a special perspective. Snow, along with a fellow student, was accused and later acquitted in a suspected hoax at the school in 1998.

In that case, authorities found more than 50 fliers with racist and anti-gay messages posted at the campus's Center for Black Culture and Learning. Police found fingerprints on the fliers that matched those of Snow and another student.

Snow said that he was wrongly accused and that his prints were discovered because he worked at the center. He said the incident might indeed have been a hoax, but not by him.

"We had students whose hormones basically were everywhere," said Snow, 27, now an elementary school teacher. "And for a majority of students, it was their first time really being away from home."

Campuses often are subject to other kinds of flimflam, say experts, such as the case involving a University of Wisconsin sophomore who allegedly staged her own disappearance and was charged April 14 with lying to police.

Whatever the motive, instant celebrity often surrounds purported victims. "Being cast as a hate crime victim creates a shield of immunity -- at least temporarily," Levin said.

Several researchers say the liberal atmosphere at many of the nation's colleges creates an environment ripe for deception.

"There's the preconception that if a charge is made, it's true," said John Perazzo, author of "The Myths that Divide Us."

"One common thread running through many such incidents is the accuser's sense of victimhood."

Jaime Alexander Saide, 19, told police at Northwestern University that he discovered the words "Die" and a Hispanic epithet scrawled on the wall near his room and on a paper stuck to his door last November. Three days later, he told police that someone grabbed him from behind, used the same slur and held a knife to his throat.

Saide's account prompted a "Stop the Hate" campaign. And the young man became a cause celebre.

"I'm not your stereotypical coffee-colored, mustachioed, short and stocky Mexican," he wrote for the school newspaper before police announced the hoax. Saide's father, a Mexican, worked as a farmhand in the United States before marrying his mother, who is white, he wrote.

But 10 days after the alleged attack, Saide admitted to fabricating the incidents, said William J. Banis, a vice president for student affairs.

Saide was arrested in connection with filing a false police report and faces two felony counts of disorderly conduct, said his attorney, Barry Spector. The maximum penalty is three years, said Spector, who refused to comment on Saide's motives. A hearing is scheduled for next month.

Saide also declined to comment, saying: "I just want to move past all of this."

In 2002, the last year for which numbers are available, 7,462 hate crimes were reported nationwide; of those, more than 10 percent occurred at schools or colleges, according to the FBI.

False hate crimes are not officially tracked, so there is no way to gauge whether they are on the rise, experts say. Since 1997, more than 20 such hoaxes have been confirmed or suspected, but many more may go unreported.

Levin, also an associate professor of criminal justice at California State University at San Bernardino, worries that hoaxes discourage legitimate victims from stepping forward because they fear they will be treated with skepticism.

To the embarrassment of liberal activists, hoaxes and suspected hoaxes have become fodder for conservatives.

"There's no question at all that these cases are used like clubs by the white supremacist right and its allies," said Potok of the Southern Poverty Law Center. He argues that hate crimes are a genuine problem. "The fact some people have actually faked these crimes really doesn't subtract from that."

Ed Drago, a junior majoring in psychology at the College of New Jersey, insisted he was a target because he is gay.

In 2001, Drago, then 25, told authorities he received hate messages and death threats. After the first two missives, a homemade bomb was found in a wooded area near the campus. Classes were canceled. At a teach-in, Drago stepped forward to address the crowd, according to the Philadelphia Inquirer.

"I didn't want to be a poster boy for the gay community," Drago told the teach-in. "But at the same time, I have to speak against the injustice."

Several months later, police arrested Drago. In March 2003, he pleaded guilty to harassment and providing false information to authorities. He was sentenced to one year probation, a $500 fine, and he paid $2,180 in restitution.

"In one way, it was a relief that it didn't really happen," said Lisa Myers, who attended the college and now serves as a campus spokeswoman. "For me, an openly gay person, it was embarrassing."

Actual or suspected hoaxes can have lingering effects. At Miami University in Ohio, the display of racist and homophobic fliers six years ago -- and the possibility that the incident was staged by a hoaxer -- still weighs on the school's president, James C. Garland. He said one of the worst consequences is that some people come away with the belief that "racial incidents and race relations are really not an issue, that it's all a trumped-up hoax or manufactured to make political points."

Still, experts say, campus hoaxes can actually help achieve some goals of the perpetrators by bringing sympathetic attention to an issue. After the incident at Miami University, officials stepped up efforts to recruit and mentor minorities.

Snow, president of the campus's Black Student Action Association at the time of the suspected hoax, said he wonders whether the campus would have changed if not for the event. For years, he pushed administrators to improve conditions for minorities.

"Ironically," he said, "everything I asked and wanted them to do, they have implemented now."

Brian Levin, an expert on hate crimes, worries that hoaxes discourage victims from speaking out.