MIDLAND CITY, Ala. (AP) -- When a gunman barged onto Charles Poland's school bus and demanded that he turn over young passengers, the driver simply said no.
"Sorry, you're going to have to shoot me," Poland told the intruder.
Moments later, Jimmy Lee Dykes did just that, killing Poland before snatching a 5-year-old boy and holing up in a homemade bunker during a six-day standoff that ended when members of an FBI hostage rescue team raided the shelter.
Poland's words were captured in an audio recording taken from a bus surveillance tape released by the FBI.
First aired Friday by ABC News, the recording confirms that the 66-year-old Poland, who has been hailed as a hero, didn't back down in the face of Dyke's threats.
"It's my responsibility to keep these kids on the bus," he said. "I can't turn them over to somebody else."
In other recordings, Dykes, 65, can be heard cursing negotiators and ranting that the standoff would cause chaos and lead to riots.
"People are going be standing up to this (expletive) dictatorial, incompetent, self-righteous, bunch of sorry bastards in government," he said.
The hostage rescue team stormed Dykes' underground bunker near Midland City in early February, killing him before he could harm Ethan Gilman or detonate an improvised explosive that authorities said was in the 6-foot-by-8-foot shelter.
The FBI confirmed the existence of the recordings but declined to immediately release the material to The Associated Press.
In interviews with ABC, FBI agents said they decided to raid the bunker after it became apparent that Dykes was handling weapons and an improvised explosive device inside the shelter more often than he had been at the beginning of the standoff.
Dykes apparently planned to have the child detonate the bomb if he was killed, said FBI Special Agent Steve Richardson.
"Jim Dykes relayed to the negotiators, 'If anything happens to me, I have told Ethan to pull the trigger,'" Richardson said. "That meant he had told Ethan to detonate the IED, the second IED that was inside the bunker."
Dykes snatched Ethan off the school bus in late January.
"I need two boys 6 to 8 years old," he is heard saying angrily in the recording. "Six to 8 years old. I mean it. Right now! Right now!"
Poland refused. "I can't do it," he responded. Seconds later, Poland said, "Sorry, you're going to have to shoot me."
"How about I shoot a kid then," Dykes replied.
Poland refused again, saying it was his "responsibility to keep these kids on the bus."
Dykes shot Poland dead moments later, and a student on the bus called 911 to alert authorities.
Once in the bunker with the child, Dykes communicated with authorities through a pipe and by phone. The recordings show he was disdainful of government and taunted negotiators with obscenities.
Authorities previously have said Dykes wanted to make a public statement about his complaints against the government but never revealed specific topics. The recording indicated he believed he could spark anarchy.
"You know goddamn well what I'd say when I go public," Dykes said. "It's going to create chaos. It's going to create riots. ... People are going be standing up to this (expletive) dictatorial, incompetent, self-righteous, bunch of sorry bastards in government."
Dykes' motive is still unclear, although he was due in court the day after the school bus confrontation on a charge of firing a weapon at neighbors.
Ethan, who turned 6 shortly after his release, was freed without any physical injuries.
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