Starting Tuesday, they'll try to convince a jury that James Arthur Ray is to blame for the deaths of Kirby Brown, of Westtown, N.Y.; James Shore, of Milwaukee; and Liz Neuman, of Prior Lake, Minn.
Ray has pleaded not guilty to three counts of manslaughter. His attorneys have said the deaths were simply a tragic accident that Ray could not have predicted.
Opening arguments will play out in a Camp Verde courtroom, about 30 miles south of Sedona where Ray conducted the ceremony in October 2009. Four months have been set aside for the trial.
A conviction on all three counts could put Ray in prison for more than 35 years.
Minutes before the sweat lodge ceremony began, he told more than 50 participants that it would be "hellacious hot," but assured them that even though they might vomit, enter into altered states of mind and feel like they're dying, they wouldn't die.
Some participants said they trusted that Ray knew what he was doing, and they set aside common sense and personal beliefs to enter and remain inside the sweat lodge. Other participants said they listened to their bodies and exited the sweat lodge when it became too much to handle.
Autopsy reports showed the 38-year-old Brown and 40-year-old Shore died of heat stroke, and the 49-year-old Neuman's organs shut down due to hyperthermia and prolonged sweat lodge exposure.
Shore and Brown were pronounced dead when they arrived at a hospital. Neuman never regained consciousness and died more than a week later at a Flagstaff hospital.
Eighteen others were injured, yet dozens emerged from the ceremony with no major problems.
Participants paid more than $9,000 each to attend Ray's "Spiritual Warrior" event with the sweat lodge meant as the highlight. Ray repeatedly told participants to hydrate but few knew why.
American Indians typically use sweat lodge ceremonies to rid the body of toxins.