Jurors have been warned about "dangerous" witnesses as they prepare to consider their verdicts in the case of former ultra-Orthodox Jewish teacher Malka Leifer.
The 56-year-old is facing 27 charges over the alleged abuse of Melbourne sisters Nicole Meyer, Dassi Erlich and Elly Sapper when she was principal of the Adass Israel School in the city's eastern suburbs between 2003 and 2007.
The mother of eight has pleaded not guilty and is standing trial in the Victorian County Court.
Her barrister, Ian Hill KC, finished giving his closing arguments to jurors on Tuesday, urging them to find Leifer not guilty.
He criticised the memories and the accounts given by the three sisters during the trial and in statements to police.
Mr Hill said Ms Sapper had told a detailed story about one alleged event in Melbourne but later changed the location to Israel.
"It's the wrong memory combined with the detail that shows you just how dangerous some witnesses can be when recounting a narrative to you," he said.
He was also critical of Ms Erlich, telling the jury that her story was constantly added to, developed and varied over the years since the allegations were first made against Leifer in 2008.
"Truth and reliability were lost in false accounts," he said.
"Perhaps even at times hardened into false imaginations and false memories of false realities."
He claimed a contemporaneous note written by Ms Erlich talked about Sem - the senior part of the girl's school - as meaning more to her than she thought it would to anyone else.
Every minute there meant a minute spent away from her tension-filled home, she wrote.
Mr Hill suggested Ms Erlich wouldn't have written that if, as she had told jurors, she was scared of Leifer.
He also questioned why the sisters hadn't spoken about their alleged shared experiences at the time, particularly given they had shared a bedroom at times and were close in age.
"The significance is if you've got this close bond as siblings and you're going through the same experiences ... that you would be talking about what is happening in your life," he said.
Prosecutor Justin Lewis said Leifer had used pretend love and concern to groom and sexually abuse the sisters for her own sexual gratification.
"These three sisters had a miserable home life and as far as the accused was concerned, they were ripe for the picking," he said.
"There's no mystery in any of them speaking highly of her - they were getting love and attention from one of the most revered and respected people they knew."
Mr Lewis asked jurors to find that Leifer had a tendency to engage in sexual activities with them and to take advantage of their vulnerability, ignorance in sexual matters and her position of authority in order to do so.
Judge Mark Gamble will give jurors directions on legal matters late on Tuesday before they retire to consider their verdicts.
