In a series of videotapes they left behind before beginning their deadly assault on Columbine High School in April, Eric Harris and Dylan Klebold bragged of wanting to "kick-start a revolution" by killing as many as 250 people, according to a Time magazine report.

"I hope we kill 250 of you," Klebold says in one of the tapes viewed by Time.

"It's going to be like [expletive] Doom," adds Harris, referring to a popular computer game. "Tick, tick, tick, tick. . . . Haa! That [expletive] shotgun is straight out of Doom!"

According to the Time report, which was based on a six-week investigation, the two young men--who killed themselves after killing 12 students and a teacher in their assault on the school last year--left behind a detailed video record that helps explain their motivations for the attack as well as their desire to become famous.

"Directors will be fighting over this story," Klebold says on one of the tapes, which includes a discussion among them of who would be the better director for their story, Steven Spielberg or Quentin Tarantino.

"You have two individuals who wanted to immortalize themselves," FBI agent Mark Holstlaw told Time. "They wanted to be martyrs and to document everything they were doing."

Jefferson County law enforcement officials, who are expected to release a report of their investigation into the shootings early next year, could not be reached for comment on the Time report.

Attempts to reach FBI officials familiar with the investigation were also unsuccessful.

The videotapes, according to Time, reveal a broader rage felt by the two young men than their widely reported antipathy toward Columbine's athletes. In one tape, Harris recalls having constantly to move with his military family and start over "at the bottom of the ladder." He also says he was picked on for his face, hair and clothing.

Klebold heaps some of the blame on his family and some on the "stuck-up" kids who hated him. "I'm going to kill you all," he says on one tape. "You've been giving us [expletive] for years."

The Time report also says the two gunmen reveal on the tapes how their parents on several occasions nearly discovered their plans, including one occasion when a gun store clerk phoned Harris's house and told Eric Harris's father that "your clips are in."

The tapes, according to Time, offer chilling new details on how Harris and Klebold saw their assault as a chance to gain respect. In one scene, Harris hefts his shotgun, makes shooting noises and says: "Isn't it fun to get the respect that we're going to deserve?"