The shooters who turned Columbine High School into an unspeakable landscape of carnage were members of a small clique of outcasts who always wore black trench-coats and spent their entire adolescence deep inside the morose subculture of Gothic fantasy, their fellow students said.
Students said the gunmen were a constant target of derision for at least four years.
"They're basically outcasts, Gothic people," said Peter Maher, a junior who had a confrontation last July 4th with the shooters and several of their fellow members of the Trench Coat Mafia, the black-clad teens' name for their clique. "They're into anarchy. They're white supremacists and they're into Nostradamus stuff and Doomsday."
Several students said the shooters were deeply into death - talking, reading and dreaming about it.
Black trench-coats are a consistent theme in the Gothic subculture. Inspired by fantasy games such as Dungeons and Dragons, Gothic has become a fascination of many American high-schoolers, some of whom simply dress and paint their fingernails black, while others immerse themselves in a pseudo-medieval world of dark images.
On Web-sites featuring poetry called "The Written Work of The Trenchcoat" and in political tracts and other elements of the conspiratorial imagination, trench-coats serve as a symbol for everything from Hitler and the Nazis, to mass murder, to suicidal fantasies.
Tuesday was Hitler's birthday, an occasion for demonstrations, mock funerals and macabre commemorations among both neo-Nazis and parts of the Gothic scene.
The Trench Coat Mafia numbered between five and 15 current and former students, always hovering on the fringes of the campus. They talked openly about blowing up the school and showed off their expertise with home-made bombs. Also, one student noted, they were particularly dirty.
The two male students suspected in the "suicide mission" and four of their friends held for questioning were described by dozens of people as outcasts, loners, social misfits shunned by most of their classmates. Meaning, they neatly fit the profiles of suspects in shooting outrages from Paducah, Kentucky, to Jonesboro, Arkansas, to Pearl, Mississippi. Disaffected boys, out to avenge social slights.
But the Colorado suspects were more militant, more visibly angry. They may have been quiet outcasts but they were noticeable ones. They were unpopular but they were well known to their schoolmates because they were so violent, so mean, so armed, so "weird", as many put it.
Which raises the question: why did not teachers, administrators and local police notice them, too?
"We don't know whether it's a new group or we're just now experiencing them," said Ms Jane Hammond, superintendent of the Jefferson County school district.
But students at Columbine had known the group for some time. Because of their appearance and demeanour, the Trench Coat Mafia came in for lots of ribbing from other students, as did the teen suspects in other school slayings, which only seemed to inflame their alienation.
"Yeah, people taunted them," said Ben Grams (17), a student at Columbine. "They hated anyone and everyone. They were just mad at the world. Mad because they weren't popular."
Student Alejandra Marsh, who said she knew one of the suspects, told a Denver TV station, "Their motive is, basically, because they hate the school and the administration . . . They've always really talked about just coming and blowing up the school."
One group member reportedly had his own Internet site, listing the people he hated, glorifying violence. A parent reported the Website to police who, she said, did nothing. And one of the suspects had a member profile on AOL listing his personal quote as, "Kill em AALLLL!!!!"
Steve Dreaden (14) was in gym class last year with a member of the clique, a boy who never removed his sunglasses. "He'd more or less hunt kids down playing dodge ball, then hit them as hard as he could," Steve recalled.
Student Mary Barnes said her brother used to hang out with them. "They played these little games, like war games, like BattleTech. But they would take them to the extreme. It's like they were role-playing."
"There were only about four or five members of the Trench Coat Mafia," said Joe Dreaden (16), Steve's brother. "Most of them supposedly graduated with seniors last year. These are just the stragglers or something."
Rumours swirled after the killings that the suspects had targeted minorities and athletes.
And, in fact, tension between athletes and gangs has been all too common. Last autumn county commissioners heard testimony from sheriff's officers about rising tension between athletes and gangs. Capt Richard Boyd said the problem was spreading to middle schools. "We are going to have to have deputies in middle schools at some point in time."
Many students acknowledged that Columbine is sharply divided, with teens squaring off into rigid cliques: the jocks, the skateboarders, the "goths", the rich kids, the brains - and the Trench Coat Mafia.
But Columbine also was an open, attractive campus in a relatively safe suburban enclave. The community is neither rural nor poor, not a place where male students would be expected to harbour such feelings of total isolation from the outside world.
But students said the clique was a world unto itself.
Joe Dreaden said a friend of a friend was in the library when the shooting began. The friend said the trench-coated shooter talked about "this being revenge about something."
Revenge for what, Joe didn't know.