Moscow (CNN)Mikhail Khachaturyan's body was found on a staircase in a Moscow apartment block in July 2018, with dozens of knife wounds to his chest and neck.
A few hours before his death, he had returned from a psychiatric clinic, lined up his three daughters to chastise them for the messy apartment and pepper-sprayed their faces, according to investigators and the sisters' lawyers. His eldest daughter Krestina, who has asthma, fainted.
That was the night that the Khachaturyan sisters -- Krestina, 19, Angelina, 18, and Maria, 17 -- decided to kill their father. They attacked him with a hammer, a knife, and the same can of pepper spray he had turned on them earlier.
Interrogation transcripts leaked to the press, and verified to CNN by a lawyer for one of the sisters, show that the women tried to inflict wounds on themselves to make it seem as if their father, who was sleeping at the start of the attack, had struck them with a knife first. Then they called the police and an ambulance.
The next day the three were arrested and confessed to the killing, saying they had endured years of sexual, physical and emotional abuse from their father, according to their lawyers and the Russian prosecutor general's office.
Last summer the sisters were indicted on charges of premeditated murder, sparking an uproar among activists in Russia, which is grappling with a far-reaching domestic abuse problem.
Legal proceedings against the sisters began on Friday, and are expected to continue for some time. The prosecution requested that sisters be banned from taking part in public events -- there are several demonstrations planned in their support -- and extend bans on internet access and talking to the media, each other and other participants of the trial for six months.
The Khachaturyans' case quickly became a cause celebre for rights groups fighting to pass a law to protect victims of domestic abuse which was shelved by parliament in 2016.
After a long and tangled pre-trial investigation, their trial opens Friday in a Moscow courtroom. The two elder sisters, Krestina and Angelina, will stand trial together. Maria, who was a minor at the time of the killing but indicted after she turned 18, has also been deemed mentally unfit to commit a murder and will be tried separately on a murder charge, according to one of the sisters' lawyers, Aleksey Liptser.