A Christian cult leader had 78 wives at a secret colony - with 24 of them underage girls, a court was told.
Warren Jeffs - who convinced his followers that he was God's spokesman on earth - faces 119 years in prison after he was convicted by a jury in Texas last week.
He was the leader at a remote colony where women were forced to dress in 19th-century outfits with hairdos similar to those seen in TV's Little House on the Prairie.
Jeffs, 55, was found guilty of sexually abusing a 12-year-old and 15-year-old girl.
"I shall send a scourge upon the counties of prosecutorial zeal to be humbled by sickness and death."
Jeffs was head of the Fundamentalist Church of Jesus Christ of Latter Day Saints - a radical offshoot of Mormonism - which has 10,000 followers and believes polygamy brings exaltation in heaven.
Prosecutor Eric Nichols told jurors how 24 of Jeffs' wives were under the age of 17.
He said Jeffs witnessed or performed more than 500 polygamous marriages, as well as 67 other marriages involving underage girls.
DNA evidence proved Jeffs fathered a child with a 15-year-old girl.
Jeffs also recorded his sex with young girls because he thought of himself as a "prophet" and had to record everything he did, hour after hour.
The court was played a sex tape of him abusing minors which left several people in the gallery in tears.
The 12-year-old victim was mentioned by name twice on the 21-minute recording, in which Jeffs could be heard breathing heavily and panting.
Prosecutors also played audio recordings in which Jeffs was heard instructing young women on how to please him sexually.
He is heard to say: "You have to know how to be sexually excited and to help each other ... and you have to be ready for the time I need your comfort."
He then orders the 12-year-old to strip and tells her not to "think about the pain" as she was "going to heaven".
Mr Nichols said: "You have heard the defendant make repeated arguments about religious freedoms.
"Make no mistake, this case is not about any people, this case is not about any religion. It is about one individual, Warren Steed Jeffs, and his actions."
Jeffs' West Texan compound was raided in 2008 and much of the incriminating material was discovered in a vault at the end of a secret passageway in the temple.
Eleven other male cult members were also charged with crimes including sexual assault and bigamy.
All seven of those who have been prosecuted were convicted, receiving prison sentences of between six and 75 years.
The jury is deliberating Jeffs' sentence.