Krakauer's new book, Under the Banner of Heaven: A Story of Violent Faith, examines a grisly murder by two brothers who belonged to one of several fundamentalist Mormon sects that splintered off the mainstream Church of Jesus Christ of Latter-day Saints. The story of religious-inspired brutality once again raises the question: Does faith promote irrational violence?
Krakauer writes that he pursued this story "for what might be learned about the nature of faith." But religious leaders and scholars of many faiths believe there is no inherent connection between religious faith and violence.
"That history doesn't lack for examples of religious violence may be true, but it is also true that history has not lacked for violence motivated by people who vigorously denied religion," says LDS church historian Richard Turley, who has read Krakauer's book.
"And if someone chooses to justify extreme behavior with extreme views of their own religion or someone else's, it doesn't mean that the religion itself teaches what (the extremists) promote." Turley notes that the killers had long before been excommunicated from the mainstream church.
This is a familiar battleground for Muslims and fundamentalist Christians.
Ever since 9/11 and Osama bin Laden's threatening videos, some have charged that Islam's holy book, the Koran, teaches hatred.
Christians too have heard accusations that their faith is a tripwire to violence. In 1978, cult pastor Jim Jones led 914 members of the People's Temple to suicide, and in 1993, David Koresh and about 80 Branch Davidian followers died in a fiery confrontation outside Waco, Texas.
Yes, there is violence in heaven's name, says Charles Kimball, a Baptist pastor, professor of religion at Wake Forest University and author of When Religion Becomes Evil. He adds suicide bombers and Hindu-Muslim clashes to the list of people who think they have "God in their pocket."
But, Kimball says, such extreme actions aren't sanctioned by religion. "Rationality does not throw out religion. I argue quite differently. We are all responsible. God gave you a brain: Use it."
Philosophy professor Michael Popich agrees that charismatic fundamentalist leaders can provoke people to "engage in acts that trump reason and moral consideration."
Brutal acts in the Bible were written in the context of history, not theological doctrine, Popich says.
The champions of genocide and murder in modern times were secular fanatics such as the Nazis, Stalinists and Khmer Rouge, says religion professor Carl Raschke of the University of Denver. "It's only been in the last 100 years that people have been able to say they weren't religious. If most people are religious, then most violence is going to be committed by religious people."
Raschke sees an inherent human trait - the fear of difference - behind religious divisions between believers and those they consider infidels.
Others see the psyche behind human brutality. Violent extremists may be atheists or believers but "that's not what is driving the violence. The psychopathology is," says Charles Bellinger, author of The Genealogy of Violence: Reflections on Creation, Freedom, and Evil.
"Studying the pathological forms of religion is not studying genuine faith," says Bellinger, who teaches theology and ethics at Brite Divinity School in Fort Worth. "Violence is actually a revolt against authentic religious faith. If you are committing murder, you reveal you are not in a genuine relationship with God."
Yet who says when faith is genuine and when it has been perverted?
Krakauer's book looks at a sect that broke away decades ago when LDS leaders, considered prophets, received new revelations updating those of the religion's 19th-century founders. The mainstream church ended polygamy and allowed blacks into the priesthood. The killers, who preferred their version of the old ways, claimed they were carrying out a revelation from God.
Krakauer, who declined to be interviewed, writes that by failing to face its history, the LDS church let such splinter sects veer off in dangerous directions.
It's a familiar concern, says Akbar Ahmed, chairman of the Islamic Studies department at American University and author of a new book on faith and fanaticism, Islam Under Seige.
For the LDS church to simply say "We are not accountable for these cults" allows them to flourish, Ahmed says. He argues that fundamentalists such as the Taliban have been able to distort the world's understanding of Islam "because they were not vigorously and effectively challenged within the Muslim world. The debate really needs to be conducted within the religion by its own scholars.
"Religion has not suddenly gone bad or been revealed as the root of evil or the cause to that effect," he says. "What is happening in the world today is the expression of evil through misinterpretation, and it must be halted and challenged by believers from within."
The answer of Christianity, Judaism and Islam is that religion is humanity's effort to "live up to the destiny of human society, to be as the Koran says, the 'deputy of God on Earth.' "