A New York woman is set to stand trial on charges she was part of a group that beat her half-brother to death during a church counseling session, an assault authorities say that went on for 14 hours over two days.

Sarah Ferguson was one of nine people charged in the attack that killed 19-year-old Lucas Leonard and put his 17-year-old brother in the hospital last October.

Her step-father, Bruce Leonard, pleaded guilty to assault Wednesday. He and Ferguson had been scheduled to be tried together Thursday on murder and other charges. Instead, he's expected to testify against her.

Authorities say leaders and members of the insular Word of Life Christian Church in New Hartford beat the brothers after they discussed leaving the congregation.

The boys' mother, Deborah Leonard, pleaded guilty to assault in December.