Former F.L.D.S. lieutenant Wendell Loy Nielsen is charged with 3 counts of bigamy for allegedly marrying three women in 2005 at the Yearning For Zion ranch near Eldorado.
Nielsen, 73, allegedly married two women on the same day.
Nielsen was a lieutenant to F.L.D.S. leader Warren Jeffs -- who's serving a life sentence plus 20 years in Texas for sexual assault of a child.
Nielsen's trial was moved from San Angelo to Midland after concerns about finding an impartial jury pool arose.
Judge Robert Moore also replaced Barbara Walther on the bench for the trial.
During Tuesday's testimony, former F.L.D.S. member Rebecca Musser verified that records seized by Texas Rangers during a 2008 raid on the Y.F.Z. Ranch were authentic religious documents.
University of Texas Family Law professor Jack Sampson also testified Monday about whether the F.L.D.S. "celestial" marriages were recognized by the State of Texas.
Finally, former F.L.D.S. Member Ezra Draper also took the stand late Monday afternoon.
The trial will pick back up Tuesday morning.
The trial could last through Friday.