Warren Jeffs, a polygamist leader, was sentenced to life imprisonment after being convicted of sexual assault charges that he claimed two young girls as his brides.

A Texas jury sentenced Jeffs on Tuesday handed down a sentence of life in prison plus 20 years, bringing to an end the trial of the controversial religious leader. Jeffs became leader of the Fundamentalist Latter Day Saints, or FLDS, when his father died in 2002.

Prosecutors say the 55-year-old sexually assaulted two girls, ages 12 and 15 years, by organizing illegal marriages under the facade of his religious beliefs. They presented DNA report showing that Jeffs fathered a child with the 15 year old girl, and played an audio recording of Jeffs allegedly having sexual intercourse with the 12-year-old.

The recording was seized when Jeffs was arrested in 2006, according to reports. He is believed to have 78 wives, with 24 of them under age 17, according to prosecutors.

Prosecutors built their case around the fact that the 15-year-old and the 12-year-old girls aren't old enough to consent to sexual activities, rather than focusing on Jeffs's multiple marriages.

So under Texas law, adults having sex with someone under 17 is a sexual assault whether the minor is willing to participate. Engaging in the same with someone under 14 year renders the crime as aggravated sexual assault and attracts a life sentence as punishment.

Prosecutor Eric Nichols told the Christian Science Monitor after court that Jeffs had "corrupted and perverted" his position of authority and the religious convictions of his own community to victimize women and children "to satisfy his own appetites and desires."

During the trial, prosecutors played an audio of Jeffs allegedly preparing five other young girls for sexual activities and encouraging them to set aside all their inhibitions, according to the Christian Science Monitor.

Jeffs was represented by stand-by counsel, appointed by Judge Barbara Walther. But on July 28, he fired his defense team and acted as his own attorney during the trial.

He had refused to attend the final stages of the trial and claimed that his prosecution was a violation of his religious rights and warned it would lead to "sickness and death" being brought on the locality, according to the Guardian.

But in just 40 minutes, a Texas jury handed down the tough sentence.

The official Mormon church did away with practicing polygamy around 1890 when the federal government put pressure down on them.

Seven other elder members of the FLDS sect, apart from Jeffs, have been convicted in Texas trials or pleaded guilty and have received sentences ranging from six to 75 years. Four more FLDS members are awaiting trial, according to the Christian Science Monitor.