(CNN) -- Court officials have released the chilling audiotapes that prosecutors say depict convicted child rapist Warren Jeffs training the girls he claimed were his "spiritual wives" to have sex with him. The audiotapes, that were key pieces of evidence in Jeffs' trial, brought some jurors to tears during Jeffs' trial. Last week, a Texas jury sentenced Jeffs to life in prison for aggravated sexual assault of a 12-year-old girl and 20 years in prison for the sexual assault of a 15-year-old girl. Jeffs, 55, had perverted his position as the head of the Fundamentalist Church of Jesus Christ of Latter-day Saints to "satisfy his own personal appetites and desires," prosecutor Eric Nichols said.
@highlight
The tapes were key pieces of evidence in the sexual assault trial of Warren Jeffs
@highlight
Jeffs, a polygamist sect leader, was convicted of sexually assaulting a 12 and 15-year-old
@highlight
Jeffs refers to having sexual relations with him as "heavenly sessions"
@highlight
'The Lord has intended that my ladies, all of my ladies be trained," Jeffs says
There is an even younger girl that the @placeholder wants me to take.
@placeholder also wrote: "If the world knew what I was doing, they would hang me from the highest tree," according to evidence presented in court.