Turley said the information in affidavits, combined with other data researched by a team that combed archives across the country, would likely result in criminal convictions for many of the perpetrators if heard by a fair-minded jury in court today. The book identifies 68 militiamen whose names have been associated with the massacre, indicating whether there is either "strong" or "inconclusive" evidence that they either planned, authorized, participated in or witnessed the murders.

Research also yielded not only names and other biographical information about the approximately 120 victims and the 17 surviving children, but a listing of their considerable property (including about 900 head of cattle), much of which ended up in the hands of massacre participants, and some of which was taken to Cedar City "and sold at a public auction held at the tithing office."

With affidavits of participants documenting the atrocities in possession of the church for decades, why did it take 150 years for such a full accounting?

"We can only do what we can do when it's our time on the stage," Turley said. "This is our time, and others have dealt with it differently. Our attitude is, look at it openly and honestly. I think that 150 years past the event, people should be about to step back and recognize that no one alive today had anything to do with the events. Though there is a lot of emotion wrapped up in it, still that emotion doesn't need to be directed at living people."

History as a weapon

Walker said in the 19th century, when the massacre "was being used as a club to hurt and destroy the church, you have to be defensive, I suppose. You have to be careful. I'm sure that played into the thinking and policy of Brigham Young. But I think this book is an expression of the strength of the Mormon culture today. Now we can take a look at some unfortunate things in our past and deal with them honestly. I think we should be happy about that."

Two religious historians who did not work on the book but have watched its progress said there were also other factors at play in bringing the depth of the historical record to light.

Jan Shipps, professor emeritus of history and religious studies at Indiana University-Purdue University, said the information age and ready access to technology have created permanent changes in the ability of any institution to keep sensitive information under wraps. For decades, most Latter-day Saints knew little or nothing of the massacre, she said.

For young Latter-day Saints learning about LDS history, "they used to send them to seminary and give them the Mormon story and that was that, and they went away from it and kept it and that's what they had in their heads when they went on their missions. Some came back and realized that was not the whole story, just the canonized story." The advent of the Internet and entire ministries devoted to attacking the LDS Church has provided "too much detailed information that's readily available" about the massacre and other sensitive topics.