As Sarah Ferguson prepares to take the stand, here's a quick primer on the Word of Life Church trial
Credit: Chris Harris

This week, witnesses and experts have been testifying in the murder trial of Sarah Ferguson, the 33-year-old half-sister of Christopher and Lucas Leonard, the teen brothers who were allegedly beaten for more than a dozen hours inside a secretive upstate New York church in late 2015.

Ferguson was arrested last fall along with several other members of the Word of Life Christian Church in Chadwicks, New York, after Lucas Leonard, 19, died from wounds he’d sustained in the alleged prolonged attack inside the secluded house of worship. His brother, Christopher, 18, was treated for lacerations and other injuries.

Prosecutors have long maintained the alleged Oct. 12, 2015, beatings were provoked by the church’s pastor, Tiffanie Irwin, who accused the brothers of molesting the children of congregants when they revealed their desires to leave the faith.

(PEOPLE has received no response to its repeated requests for interviews with church representatives and each of the respective defendants’s attorney, to discuss the beatings and the prosecution’s allegations)

As Ferguson prepares to take the stand in her own defense, here are five things you should know about her trial, which could be turned over to a jury early next week:

1. Lucas Leonard’s sister testified that her brothers sexually abused her

In separate testimony given on Tuesday, Grace Ferguson, Christopher’s sister, told the court that both of her brothers had allegedly touched her in a sexual manner.

The 16-year-old girl testified that the alleged inappropriate touching began when she was 4-years-old and ended when she turned 13.

She further claimed in court that Lucas Leonard had allegedly said he wanted to leave the church only so he could molest little girls free of consequences. She also told the judge that she moved in with Ferguson last year, after her brother Lucas watched her take a shower.

2. Christopher Leonard admitted molesting children of church members

Christopher Leonard has testified that he and his deceased brother had molested the children of several Word of Life Church congregants, including Ferguson’s infant child.

From the witness stand, Christopher said he touched the children of some of the church’s members, but denied ever having intercourse with them.

The unexpected revelation came Monday inside Oneida County Court, but it is unclear at this stage whether Christopher’s disturbing disclosure will help the defense.

3. Bruce Leonard, Christopher’s father, thought the alleged beatings would help his sons

On Wednesday, Bruce Leonard, wearing an orange prison jumpsuit, testified that Tiffanie Irwin allegedly called his family together following a Sunday service and then confronted the siblings with allegations of child abuse and witchcraft.

Leonard told a judge that the alleged beatings began with a punch and a slap, and quickly progressed to electrical cord whippings.

Leonard testified on Wednesday that the alleged beatings were carried out so that his sons “would understand the hurt that they caused,” and to discipline and punish them.

Bruce Leonard told the court that the alleged beating finally stopped after Lucas Leonard sustained an injury to his genitals. According to court records, Lucas bled out from a laceration to his genitals, causing his death.

Leonard further testified that he told his sons that “blows that hurt drive off evil” as he allegedly whipped them.

4. Experts believe the Word of Life Church is a bona fide cult

Rick Ross, who founded the Cult Education Institute, based out of Trenton, New Jersey, tells PEOPLE he’s carefully analyzed the group, and believes it “fits the core definition of a destructive cult.”

Ross claims the Word of Life Christian Church is, like many cults, a “small, family-based groups like this is, with members who’re largely related. And in this group, if you left the church, you were damned.”

Ross says the church’s leaders utilized thought reform and coercive persuasion to indoctrinate new members. He says from his analysis it appears “the church existed solely for the benefit of the Irwin family.”

Adds Ross: “From what I can tell, church leaders broke people down through coercion, persuasion, isolation, and the control of information. They would break them down and then mold them into a subservient mindset. The members were under the undo influence of the church’s leader, and they were not allowed to talk to people that left the church or people outside of that group.”

5. Former members agree the church had dangerous effects on its members

Former Word of Life Christian Church member Nathan Ames tells PEOPLE the church had changed drastically over the years from a place of worship to an alleged house of torment.

“There were a lot of good things that had been going on at the church, but it slowly and increasingly got controlling,” Ames, 26, alleges to PEOPLE. “People were being mentally abused over time and they’d become sheltered from the outside world as a result. It got to the point where, if you watched television, you shut the commercials off because you didn’t want any external influences.”

Ames says his parents decided to exit the congregation 13 years ago, soon after the death of its founder, Jerry Irwin. He says his parents couldn’t continue to witness the organization gradually decline into what he alleges is a reclusive and dysfunctional group.

“Normal churches are not like this,” Ames says. “This is not what a real church is. It’s sad that people see this and think that’s what church is. I think it’s a cult simply because mind control was used, and because the Irwins made claims that they were the only way to heaven. People believed that.”