A 47-year-old man has been charged with the domestic violence murder of his 90-year-old grandmother after she was found dead in Sydney’s east.

Valentina Spivak was discovered with significant injuries inside a unit on Chambers Avenue, Bondi Beach, after emergency services were called over reports of a stabbing about 5.15pm on Saturday afternoon. Paramedics attempted to save her, but she died at the scene.

Sergei Mitnik was arrested at the unit and taken to Surry Hills police station on Sunday. NSW Police Detective Superintendent Jodi Radmore told reporters Mitnik was “cooperative with police at the scene” .

He later appeared dishevelled and in handcuffs via video link in bail court on Sunday. His lawyer raised serious concerns about his mental health, saying a psychiatrist appointment scheduled a month earlier had been cancelled and that he was experiencing effects from the weight loss drug Ozempic. He did not apply for bail and is due to face court again this week.

Neighbours have since paid tribute to Spivak, describing her as a “gentle soul”.

“She was always listening to this old Russian opera, you could really hear it in the hall,” one neighbour said.

“Definitely nothing bad to say about her to be honest, she was a nice woman,” another resident said.

Spivak was one of three women allegedly killed by men they knew in a 24-hour period across NSW.

In a separate case, a man was charged over the alleged stabbing death of a 23-year-old woman at a home in the Riverina region.

In another unrelated incident, a man was charged with murder over the death of a 70-year-old woman at Mole River in the NSW Northern Tablelands.

Premier Chris Minns acknowledged the deaths in a statement on Sunday.

“Families are today dealing with unimaginable grief,” Minns said.

“My thoughts are with the families, loved ones and the communities of the women who have died,” Minns said.