WASHINGTON — That Tuesday's school shooting in Littleton, Colo., occurred on Adolf Hitler's birthday was almost certainly not a coincidence.

In fact, hatemongering, particularly by neo-Nazi groups, seems to be at the root of the shooting.

That was borne out by numerous reports that surfaced in the days after the massacre in which two heavily armed students opened fire in their suburban Denver high school, killing at least 12 students and one teacher before killing themselves.

Those reports described the two perpetrators, Eric Harris and Dylan Klebold, as belonging to a group — known as the "Trenchcoat Mafia" — that wore Nazi symbols and that painted graffiti, including swastikas, in the school's bathroom.

Classmates at Columbine High School told local media that members of the group had been obsessed with World War II Germany and had spoken openly about April 20 being Hitler's birthday. They also adopted Gothic attire and championed white supremacy.

And although no victims were believed to be Jewish, Dr. Carl Raschke, author of "Painted Black," which explores violent youth culture, told the Denver Post it appears that the group operates under "a heavy code of neo-Nazism."

The fact the massacre occurred on Hitler's birthday "probably explains a lot more than we want to imagine," he told the newspaper.

"These kids see themselves as young storm troopers," said Raschke, a professor of religious studies at the University of Denver. "They want to honor the memory of the master, and these kids seriously look to Hitler the same way that young blacks look to Martin Luther King and the way many Christians look to Jesus."'

Although the students may have had neo-Nazi ties, they apparently did not target Jews in the shooting.

Aaron Cohn was hiding under a table in the Columbine High School library when one of the perpetrators pressed a gun to his head.

"All jocks stand up. We're going to kill every one of you," the gunman said, according to Cohn.

Cohn told local media that his life was spared when the shooter shifted his attention to a black student nearby and fired, saying, "I hate niggers."

Doctors said 12 of the 15 dead, including the assailants, were found in the library where Cohn hid.

Another student, Jenni LaPlante, told the Denver Post she had asked members of the six-member group, "'Why do you guys wear all that German stuff? Are you Nazis?' And they would say, 'Yeah, Heil Hitler.'" LaPlante told the newspaper she never knew whether the suspects were joking or not.

Only a handful of Jewish students attend the high school, according to local residents. One has complained of an anti-Semitic atmosphere created by the same "jocks" targeted by the shooters this week.

Steven Greene, the father of one Jewish student at the school, has complained to school officials about a climate of anti-Semitism, according to the Intermountain Jewish News.

Although Trenchcoat Mafia appears to have adopted some neo-Nazi ideology, it does not appear to be central to their beliefs, according to Anti-Defamation League officials in Denver who have been in touch with the local police. The police said they found hate material in the suspects' homes.

And two months earlier, researchers at the Simon Wiesenthal Center, who have identified more than 1,500 Internet sites espousing hate and bigotry, had come across two sites promoting anarchy that were apparently linked to the Littleton student group.

"There have always been misfits and outsiders at schools, but what we seem to be getting now is a whole subculture coming together online and magnifying the chances of mayhem," said Rabbi Abraham Cooper, associate dean of the Los Angeles-based Wiesenthal Center.

In their rampage, police said, the shooters deployed lethal pipe bombs, propane-filled shrapnel explosives, and plastic containers filled with gasoline and soap.

During a news conference Wednesday in Los Angeles, Cooper displayed illustrations taken from a dozen Web sites, giving precise instructions on how to make such deadly weapons.

"We can't blame the government or police for what happened," Cooper said. "It's a matter of education, and also high time for Internet service providers to set standards for dealing with hate groups using their services.

Abraham Foxman, ADL's national director, agreed. "Education is the only antidote we have to racism, bigotry and anti-Semitism."

But, he added, "there's no vaccine or silver bullet."

ADL's "World of Difference" curriculum on tolerance has reached 400,000 teachers, Foxman said, suggesting that tolerance education should be elevated to the same status given English, math and science.

The Wiesenthal Center on Wednesday sent a letter to President Clinton, urging him to recommend a national curriculum on tolerance and civility for all of America's schools.

Some are questioning the laws that prevent police from investigating a group until a crime is committed.

"Maybe we should re-examine" such laws "within constitutional standards," Foxman said. "We have to be a lot more creative to be proactive to find out what these groups are."

As the community reeled from the shock of Tuesday's events, Rabbi Fred Greenspahn of Congregation Beth Shalom in Littleton searched for ways to stem the tide of teenage violence.

"Who are these kids, and why do these things happen?" Greenspahn said in a telephone interview. "We need to sort out what's around in our world that's facilitating this kind of thing happening."

In Denver, the Jewish community canceled its planned celebration of Israel's Independence Day on Wednesday evening, choosing instead to hold a memorial service for the victims. An Israeli youth choir visiting for the Yom HaAtzmaut event was scheduled to sing both at the Jewish community-sponsored memorial as well as a vigil sponsored by the city of Denver.

In the meantime, many continue to search for answers.

"It's important for us to understand this does not only happen in places we associate with violence," said Greenspahn, who said he planned to hold a discussion about the shooting during services this weekend.

"This is not a problem of them, it's a problem of us."