Jurors in the first criminal trial following the raid of a polygamist group's Texas ranch have convicted a member of sexual assault of a child.

Thirty-eight-year-old Raymond Jessop was convicted Thursday of the charge that stemmed from his alleged marriage to an underage girl.

He's the first group member to face a criminal trial since Texas authorities raided the Fundamentalist Church of Jesus Christ of Latter Day Saints' ranch in Eldorado last year.

Prosecutors say the girl was brought to the Yearning For Zion Ranch at age 15 and entered a so-called "spiritual" marriage with Jessop. She became pregnant at 16.

Defense attorneys argued prosecutors failed to produce a witness that placed Jessop in Schleicher County at the time of the alleged assault.