MOSCOW - Russian lawyer Mari Davtyan has built a reputation as a go-to advocate for women abused by spouses, boyfriends and fathers. Now she’s defending three teenage sisters who battered and stabbed their father to death in his sleep in their Moscow apartment after allegedly suffering physical and sexual abuse from him for years.

She believes the Khachaturyan sisters' case is helping to shift Russian attitudes toward domestic abuse and how victims should be treated.

Murder Trial of 3 Teenage Sisters Changing Russian Minds on Domestic Violence

Police investigators have confirmed the girls' father, 57-year-old Mikhail Khachaturyan, abused the teenagers for years, regularly beating and torturing them as well as sexually assaulting them. A regular churchgoer, the rage-filled abuser saw himself as a righteous man and considered domestic violence as no sin — a not uncommon view among Russian men.

Murder Trial of 3 Teenage Sisters Changing Russian Minds on Domestic Violence

However, the shocking case of the Khachaturyan sisters — Angelina, Maria and Kristina — may mark a turning point when it comes to attitudes, even of men, toward domestic abuse. Moreover, it is adding public pressure on judges and the government to rethink how they treat domestic abuse victims, the Armenian-born Davtyan said.

Murder Trial of 3 Teenage Sisters Changing Russian Minds on Domestic Violence

Davtyan acknowledges that in the last few years domestic violence and abuse has started to be taken more seriously in Russia. There are, however, no laws protecting domestic abuse victims and in 2017 there was an outcry when a new law offered only a fine or two-week sentence for a first-time offender who beats up a family member. Many police still ignore domestic abuse complaints, dismissing violence within homes as a “family issue.”

Rights activists estimate women in as many as one in every four Russian families suffers abuse at the hands of male partners. There are only estimates — no domestic abuse data is collected by law-enforcement agencies. Masha Tvardovskaya, a coordinator for Stop Violence, an organization funded in part by Britain’s Charities Aid Foundation, says it is not only male spouses and partners who are the problem. “Old women face violence from their sons, too,” she says.

Charged with murder after the July 2018 killing, the sisters' plight has prompted a wave of public sympathy — and even unusually gentle handling from police investigators, Davtyan said. As the horrific details of the girls’ lives have unfolded, their case has turned into a cause célèbre, one that’s triggered questions about why their school and local child services, both of which were tipped off about the abuse, failed the girls and didn’t intervene.

It is also provoking demands for better safeguarding. More than 300,000 people have signed a petition calling for their release. Rights activists and women’s groups want to see new measures introduced and are campaigning for state-funded shelters, restraining orders and domestic-abuse training for judges and police.

According to Davtyan and the girls’ other lawyers the father even shot at them with a BB gun. After he kicked their mother out in 2015, the daughters became slaves. They couldn’t leave the apartment without his permission and were kept back from school for long periods. He installed cameras to monitor their every move and defiance was met with rage and violence. He’d pepper spray and thrash them for failing to perform household chores to the standards he expected.

Sitting in the conference room of a downtown Moscow office, Davtyan, a mother of a 6-month old boy, said the girls are deeply traumatized. The sisters' case is moving slowly, with another procedural hearing expected later this month. The girls aren’t in custody, but their movements are restricted and they’re not permitted to speak to the media or each other.

“They have been diagnosed with post-trauma nervous breakdowns. They all have personality disorders from the abuse,” Davtyan said.

She said the sympathetic media coverage of their case “helps them to understand they’re not alone.'

'It’s very important for them. I think today the girls see people are trying to help them in the way no adults did before. I think it’s very important for them to know that their lives matter and they’re not alone in the way they were when they were being abused and the adults around them failed to help.”

Prosecutors say the killing was premeditated and that the sisters coordinated their actions, with Angelina wielding a hammer, Maria using a hunting knife and Kristina using pepper spray. Their motive was revenge, hence the murder charge, prosecutors say. If found guilty the sisters could be sentenced to 20 years in jail, but with public pressure mounting, the charges against them could be reduced.