Polygamist Warren Jeffs is flanked by Las Vegas Metro Police SWAT officers during an extradition hearing at the Clark County Regional Justice Center in Las Vegas in this August 2006 file photo. (Steve Marcus/REUTERS)

Warren Jeffs was sentenced to life in prison in Texas on Tuesday, after being convicted of sexually assaulting two child brides, ages 15 and 12, the Christian Science Monitor reports.

The conviction came after a bizarre trial in which prosecutors tried to prove the polygamist sect leader was a pedophile while Jeffs insisted on representing himself but remained silent for much of the proceedings. Jeff presented just one witness — a leader of the sect who gave what the Associated Press called “an extended Sunday school lesson” on the church’s beliefs.

(See early LIFE photos of polygamist communities here.)

After the conviction was announced, prosecutor Eric Nichols said Jeffs had “corrupted and perverted” his position of authority so that he could use women and children “to satisfy his own appetites and desires.”

Prosecutors used DNA evidence to show that Jeffs had fathered a child with a 15-year-old girl. They also played tapes in which Jeffs asked young women to please him sexually, telling them it would please God.

Jeffs is the leader of the Fundamentalist Church of Jesus Christ of Latter-day Saints (FLDS), which is not affiliated with the Church of Jesus Christ of Latter-day Saints, or Mormon church.

FLDS followers believe that polygamy is a means of gaining divine acceptance. Jeffs has 78 wives, in addition to his legal spouse. Twenty-four of them are under the age of 17.

In 1944, Life magazine photographer John Florea traveled to Salt Lake City with an assignment “to study the burgeoning, defiantly devout kind of American family that still fascinates us today: polygamists.”

Florea chronicled the day-to-day life of farmer and carpenter Joseph Lyman Jessop, who lived with his three wives and their 25 children. (John Florea /LIFE.com)