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.
Domestic violence experts, along with the sisters' defense team, say that in the absence of adequate protective mechanisms within law enforcement and the court system, their only choice was to defend themselves or eventually die at their father's hands.
In text conversations obtained from their father's phone and published on Facebook by Liptser, Mikhail Khachaturyan appeared to have threatened to kill them and sexually abuse them and their mother.
"I will beat you up for everything, I will kill you," says one text from April 2018, accusing them of having sexual relations with a male friend. "You are prostitutes and you will die as prostitutes."
The interrogation transcripts also painted a chilling picture of mental, physical and sexual abuse dating at least four years prior to the killing.
"We think that they had no other choice. The father drove the girls to despair, their whole life was a continuous hell. They cannot be compared to healthy, calm and balanced people ... [the] girls developed serious mental illnesses, including abuse syndrome and post-traumatic stress disorder. This was confirmed by all examinations in the case," said one of the sisters' lawyers, Aleksey Parshin.
Since last summer, activists have organized dozens of demonstrations in support of the sisters under the "I did not want to die" campaign, calling on authorities to reclassify the case around the sisters' self-defense.
A 2019 investigation by Media Zona, a Russian outlet covering justice and prisons, said that almost 80% of Russian women imprisoned for premeditated murder in 2016-2018 were trying to protect themselves from an abuser.
While Russian lawmakers have left the domestic violence bill on the backburner since 2016, they did find time to decriminalize some forms of abuse three years ago.
At first, public pressure seemed to have turned the case around for the Khachaturyan sisters.
In January, the prosecutor's office confirmed allegations made by the defense that the Khachaturyan sisters had suffered "beating, constant humiliation, threats and abuse, physical and sexual violence," and that they had developed a "defensive reaction."
The prosecutors then ordered the Investigative Committee to reclassify the case from premeditated murder to necessary self-defense.
Parshin told state-news agency TASS at the time that the move "essentially means the end of a criminal investigation" against the sisters, who faced up to 20 years in prison under the premeditated murder charge.
But in a stunning reversal, Viktor Grin, the same prosecutor who first recommended downgrading the case, confirmed in May that premeditated murder charges would indeed be laid against the sisters. No explanation was given for the change.
Mari Davtyan, a lawyer for the sisters who often represents victims of domestic abuse, linked the reversal to a wider trend of dismissing human rights that has been growing since the passage of controversial amendments to the Russian constitution following a referendum on July 1.
"I think it's impossible not to notice what's been going on every day since July 1, 2020, the state has chosen its path," Davtyan wrote on her Facebook page. "And the Khachaturyan case is no exception."