On one level, they were the usual group of school outcasts who endured taunts and teasing.
But something terribly volatile was added to that mix in a well-to-do suburb just south of Denver that caused the worst school shooting in US history.
It may be the availability of guns, a lack of parental guidance, the ease of learning how to make a bomb on the Internet, or perhaps just a culture that too often glorifies violence.
In the wake of the tragic incident here, experts are looking - once again - for reasons behind the seemingly inexplicable episodes of school violence.
While no simple answers - or solutions - exist, the rampage in a suburban high school here is focusing attention on a "gothic" subculture and dark cliques that exist at many schools across the United States.
"These are youth who are alienated and angry and armed, and they are often ostracized by their peers," says Dewey Cornell, director of a youth violence project at the University of Virginia in Charlottesville. "So they come together as a kind of marginal outsider group, and they are attracted to counter-cultural ideas and images, which may range from neo-Nazism to the occult."
Experts say many of these young men are of above average intelligence, have talents and capabilities, but for many reasons feel alienated from their peers.
One expert said the trench-coat-wearing suspects and their buddies fit a profile of obsessed youth.
"It's pretty clear to me this is a self-styled and self-named group, but it follows a pattern we've seen in other high school terrorist incidents," Carl Raschke, author of a book on violent youth culture, told a Denver paper. "It appears you have a bunch of kids who have been into black metal music, who basically have apocalyptic fantasies and [who operate under] a heavy code of neo-Nazism."
Preliminary reports indicate that the suspects in the case, Columbine High School students Dylan Klebold and Eric Harris, executed a well-planned attack on their fellow students and teachers, killing approximately 15. Klebold and Harris were both found dead in the school library of self-inflicted gunshot wounds, police say.
Experts note that it's ironic that levels of violence among urban youth and gangs is down, but that of teens in the suburbs has not received the same amount of attention.
"We've overlooked it in places where everyone thinks 'it can't happen here,' " says Mr. Cornell.
Even before the names of the two alleged shooters were confirmed by police, students were quick to name them as the members of the "Trenchcoat Mafia," given their preference for wearing black trench coats, even on warm days.
Jeannie Plato, a student, says one of her friends once dated a member of the group. She put the number of core members at 12, but said as many as 30 might consider themselves members to some degree. Jeannie says all of the members were boys, although their girlfriends would also hang out with the group.
Students gave varying accounts of the group's fetishes. Some say the boys were obsessed with World War II and wore Nazi crosses. Police say they were aware of the fact that the shooting occurred on Hitler's birthday, but were not sure of any connection at this point.
Others say the Trenchcoat Mafia favored "gothic" music that talks of death and destruction. Combat boots and black pants were also favored by group members.
One student told a newspaper that Trenchcoat Mafia members threatened him and his friends with a shotgun. They never saw the shotgun, but the trenchcoat boys did pull knives and fight with others.
Students say the group members themselves would acknowledge the name Trenchcoat Mafia. The group reportedly took out a page in the high school yearbook with some of their photos.
"Who says we're different?" says the caption, according to one press account. "Insanity's healthy ... Stay alive, stay different, stay crazy."
In turn, students say the group was open to ridicule. Jeannie says some mocked the group by dressing up as Trenchcoat Mafia members for Halloween.
"You need some new clothes," was one remark directed at them, 10th-grader Mindy Pollock told one newspaper. But Mindy added that it was "just stupid teenage stuff."
This type of teenage alienation isn't necessarily new. It does evoke echoes of James Dean and "Rebel Without a Cause" from the 1950s. But what's different now, experts say, is that, instead of fistfights and motorcycles, these teens are picking up guns and making bombs.
Still, analysts caution that it's too early to tell whether groups such as the Trenchcoat Mafia are on the rise.