People.com Crime Sister Found Guilty of Manslaughter in Fatal Beating at 'Killer Cult' New York Church Court officials tell PEOPLE Ferguson, 33, was also convicted on two counts of gang assault stemming from the Oct. 11, 2015, beatings of her half-brothers Christopher and Lucas Leonard By Chris Harris Chris Harris Twitter Chris Harris has been a senior true crime reporter for PEOPLE since late 2015. An award-winning journalist who has worked for Rolling Stone and MTV News, Chris enjoys prog rock, cycling, Marvel movies, IPAs, and roller coasters. People Editorial Guidelines Published on July 5, 2016 04:45 PM Share Tweet Pin Email Photo: Tina Russell/Observer-Dispatch/AP Sarah Ferguson, who participated in a gang assault last fall that killed her 19-year-old half-brother and severely injured her then-17-year-old half-brother at an upstate New York church, was convicted of manslaughter and assault but was cleared of murder on Tuesday, PEOPLE confirms. Court officials tell PEOPLE Ferguson, 33, who pleaded not guilty prior to the bench trial, was also convicted of two counts of gang assault stemming from the Oct. 11, 2015, beatings of her half-brothers Christopher and Lucas Leonard. The violence took place inside the building of the Word of Life Christian Church in Chadwicks, New York, which some experts and former members maintain is a cult. Lucas, who was 19, died from injuries he sustained in the beatings, which were carried out over more than a dozen hours. Christopher, now 18, was left with cuts, abrasions, and other wounds in the attack, which, at times, involved whippings with electrical cords. Prosecutors say the beatings began soon after both brothers approached church leaders with their plans to defect. It was unclear at press time why Ferguson was cleared of the murder charge while being found guilty of the manslaughter charge. Ferguson faces up to 50 years in prison when sentenced on Sept. 1. The verdict was issued hours after lawyers for the prosecution and defense presented their closing arguments. • Want to keep up with the latest crime coverage? Click here to get breaking crime news, ongoing trial coverage and details of intriguing unsolved cases in the True Crime Newsletter. Last week, Bruce Leonard, the 66-year-old father of the two teens who were beaten inside the Word of Life Church, took the stand in Oneida County Court, providing a detailed account of the incident that took his 19-year-old son’s life. Leonard described how he and several other members of the church allegedly pummeled and whipped his two teen sons during a church counseling session. The father, one of the prosecution’s star witnesses, sobbed at times as he recalled the reason for the alleged prolonged gang attacks: Both brothers had been accused of sexually abusing their sister, Grace, as well as the children of Sarah Ferguson. Bruce Leonard was originally set to stand trial with his daughter, but accepted a plea bargain for two counts of assault last week. He faces 15 years behind bars. During testimony last week, Christopher Leonard admitted he and his brother had molested the children of several church members – including Ferguson’s infant child – the night before the beatings. He denied ever having intercourse with any of the victims. Prior to Leonard’s testimony, prosecutors had long claimed the allegations of abuse against the Leonard brothers were baseless. In separate testimony Tuesday, Grace Ferguson, Christopher’s sister, said both of her brothers had touched her in a sexual manner. Multiple church members have been charged in Lucas’s death. The other defendants in the case are expected to go on trial in September. Those with outstanding criminal charges stemming from the beatings include pastor Tiffanie Irwin; Irwin’s mother, Traci Irwin; and Tiffanie’s brothers Joseph and Daniel Irwin. Mother and son Word of Life members Linda and David Morey are also facing charges. All have pleaded not guilty. The parents of the beating victims – Bruce and 60-year-old Deborah Leonard – have both accepted plea bargains for assault from the prosecution. They have agreed to testify against the seven other defendants facing charges for their roles in last fall’s violence.