Story highlights Attorney General Greg Abbott's office: Move marks the final chapter of a nearly 5-year effort

In August 2011, a Texas jury found sect leader Warren Jeffs guilty of child sexual assaults

The Fundamentalist Church of Jesus Christ of Latter-Day Saints practices polygamy

Sect members have denied any sexual abuse takes place

The Texas Attorney General's Office said Wednesday that it has started legal proceedings to seize the 1,600-acre ranch where prosecutors say polygamist sect leader Warren Jeffs and others sexually abused children.

Greg Abbott's office said the move marks the final chapter of a nearly five-year effort to pursue widespread criminal misconduct charges at the Yearning for Zion ranch near Eldorado, Texas.

Four hundred children were removed from the complex, then returned after the Texas Supreme Court ruled the state had no right to remove them and lacked evidence to show they were in imminent danger of abuse.

Child protection officials said they found a "pervasive pattern" of sexual abuse on the ranch through forced marriages between underage girls and older men.

In August 2011, a Texas jury found Jeffs guilty of sexual assault against two girls, ages 12 and 15. He is serving a life sentence.

The Fundamentalist Church of Jesus Christ of Latter-Day Saints openly practices polygamy on the YFZ Ranch, as well as in the twin border towns of Hildale, Utah, and Colorado City, Arizona. Critics of the sect say young girls are forced into "spiritual" marriages with older men and sexually abused.

Sect members have denied that any sexual abuse takes place. Their attorneys were not immediately available for comment.