The investigators' report of the Columbine massacre fleshes out portraits of the killers and fills in many logistical details of the attack, but concedes "it cannot answer the most fundamental question -- WHY?" It was released Monday on CD-ROM by the Jefferson County Sheriff's Department, following six months of delays. "Although no clear-cut answers were found, there were clues," the report says.

The central focus of the package is a minute-by-minute timeline describing the events of April 20, 1999, in great detail. It dramatically collapses the amount of time the massacre took to unfold, claiming gunmen Eric Harris and Dylan Klebold only spent seven and a half minutes in the library, killing 10 and wounding 12. "They carried more than enough ammunition to kill all 56 people in the library," it says, adding that the 34 victims were killed or injured in the first 16 minutes of the attack. After the killing rampage, there were 33 minutes in which nobody was shot until the gunmen killed themselves.

The report provides the most comprehensive profiles yet of the killers, offering newly disclosed passages from a variety of sources, including school essays, journals kept by both killers and interviews with the killers' parents. While some information was known about Harris because of his Web site, and passages from his journal published by Salon, one of the biggest surprises in the report is writings from Klebold. Klebold's newly revealed journal depicts him as depressed, outcast, paranoid and suicidal. "I swear -- like I'm an outcast, and everyone is conspiring against me," he wrote in 1997. He mentions suicide repeatedly and in November 1997 describes getting a gun and going on a killing spree.

His tone changed only briefly in 1997, during a period where he describes his "first love." "It appeared that this was an unrequited love," the report says. "Throughout his journal, Klebold named several girls he 'loves' but he did not indicate that he ever actually spoke to any of them. He even went so far as to write letters to one girl but it appears he never sent them because they remained in his journal."

Harris' journal doesn't begin until the spring of 1998. The report describes it as expressing Harris' hatred of mankind and love of his own anger, though it omits the journal's opening line, which sets its tone: "I hate the fucking world."

"There were also many common themes throughout their writings. Harris and Klebold both wrote of not fitting in, not being accepted and their lack of self-esteem. They reflected on natural selection, self-awareness and their feelings of superiority. They plotted against all those persons who they found offensive -- jocks, girls that said no, other outcasts or anybody they thought did not accept them. Most of those teens were unaware that they had ever offended Harris or Klebold."

Klebold's journal provides evidence confirming what investigators have been saying for months: that Harris and Klebold were both involved in the planning of the attack. Shortly after the shooting, media reports focused on Harris as the mastermind, casting Klebold as a somewhat reluctant follower. The report also states that a "hit list," generally attributed to Harris, was created by both killers, and puts the final figure of people whom they listed as disliking for various reasons at 67. It does not reveal the names, though in September, lead investigator Kate Battan told Salon News that the list included some unusual names, including Tiger Woods.

Investigators had repeatedly said that no one on the lists was killed or injured, but the parents of Rachel Scott strongly protested in December that comments on the videotapes clearly identified their daughter. The report concedes that one person on the list was "injured," but that the person was a male. "There is no evidence that he was specifically targeted," the report says.

Investigators could not pinpoint exactly when Harris and Klebold began conspiring to commit the massacre, but the earliest evidence of mutual understanding occurred a year before the attack.

In April 1998, Klebold made four entries in Harris' yearbook. One referred to "the holy April morning of NBK [Natural Born Killers]." Another includes the lines "killing enemies, blowing up stuff, killing cops!! My wrath for January's incident will be godlike. Not to mention our revenge in the commons." The reports says investigators believe the January incident referred to their arrest for breaking into a vehicle on Jan. 30, 1998. The main bombs were set to go off in the commons. The report says that those bombs could have killed all 488 people in the cafeteria. It also concludes that the casualties were a fraction of the number intended chiefly because Harris and Klebold were poor bomb makers.

Harris made similar entries in Klebold's 1998 yearbook: "God I can't wait till they die. I can taste the blood now - NBK" [Natural Born Killer] ... You know what I hate? ... MANKIND!!!! ... kill everything ... kill everything." He also drew a gunman standing amid a sea of dead bodies with a caption: "The only reason your [sic] still alive is because someone has decided to let you live."

Investigators also retrieved eight pages Klebold apparently wrote and drew just a day before the attack, discovered in his notebook along with his math homework. "About 26.5 hours from now the judgment will begin," one passage began. "Difficult but not impossible, necessary, nervewracking and fun. What fun is life without a little death? It's interesting, when i'm in my human form, knowing i'm going to die. Everything has a touch of triviality to it."

The report also seems to downplay the significance of the Trench Coat Mafia, another focal point of many of the stories just after the shooting. It states: "Although the investigation identified Harris and Klebold as being 'members' of the TCM, it appears that the Trench Coat Mafia was a loose, social affiliation of former and current Columbine High School students with no formal organizational structure, leadership or purpose such as that typically found in traditional juvenile street gangs. Contrary to reports following the Columbine shootings, there is no evidence of affiliated Trench Coat Mafia groups nationwide."

Previously, investigators had minimized the pair's role in the group, characterizing them as "fringe members." In an exclusive interview with Salon in September, Battan repeatedly scoffed at the notion of any significant association: "They were outcasts in that!" she said.

Some families were left unsatisfied and angry after the report's release, accusing the sheriff's office of continuing to withhold crucial information. Brian Rohrbough, whose son Dan was killed in the attack, characterized the report as full of lies and contradictions in an interview on the local CBS affiliate. "They want to show it to be much more confusing than it was," he said. "And they want to build in a lot of excuses."

"Certainly they're not going to tell the truth," said Judy Brown at an impromptu press conference when the report was distributed. "People are going to be so outraged when they hear the truth." The Browns alerted officials to Harris' death threats and Web site months before the attack, and play a key role in several of the families' lawsuits. They have begun the process for a recall of Sheriff John Stone. Brown's son escaped unharmed from the school the day of the assault.

"If you're preparing for a lawsuit, one of the most major lawsuits in the United States, and you have all the information, do you think you're going to give everything out?" Brown's husband, Randy, added. "I think you're going to release the best version of this that's going to do best for your lawsuit."

The report reiterated several statements repeated frequently by investigators: It ruled out a third gunman or conspirator, said Harris and Klebold hoped to kill hundreds and concluded that a failed bomb outside the school was intended to divert police longer. "The failure of the cafeteria bombs to detonate and the arrival of responding officers apparently caused the gunmen to reevaluate their planned attack, since they had never listed the school library as a destination point," it said.

It explained the third-gunman confusion as coming both from Harris' removing his trench coat quickly and the sighting of a "shooter" on the roof who turned out to be an air-conditioning repairman.

Sheriff's officials refused to comment on the report, citing the pending litigation brought by several families. Copies of the report will be available to the public, beginning Tuesday, for $12 plus tax and shipping. They can be ordered by phone at (720) 317-1131, fax at (720) 449-7553 or e-mail at Columbine@wcox.com.