A Sydney man accused of killing his 90-year-old grandmother in her Bondi Beach home has been charged with murder, while his lawyer has raised mental-health concerns and told a court that the accused believes the weight-loss drug Ozempic had affected him.

Sergei Mitnik, 47, was arrested at a unit on Chambers Avenue on Saturday, September 19, after emergency services were called about 5.15pm following reports of a stabbing. NSW Police said officers found a 90-year-old woman with significant injuries to her torso. Paramedics treated her at the scene, but she died.
The woman has since been identified in media reports as Valentina Spivak, Mr Mitnik’s grandmother. Police charged Mr Mitnik with domestic violence-related murder and refused him bail ahead of his first court appearance on Sunday.
The case is at an early stage. The charge is an allegation and Mr Mitnik is entitled to the presumption of innocence unless and until guilt is proved in court.
What the court heard
During the Sunday bail hearing, Mr Mitnik’s solicitor, Javid Faiz, told the court he wanted concerns about his client’s mental health addressed as early as possible. Reporting of the hearing said Mr Faiz referred to a psychologist appointment that had previously been cancelled and asked that Mr Mitnik receive a psychological or psychiatric assessment.
The court also heard that Mr Mitnik had been using Ozempic after it was prescribed for weight loss. Mr Faiz said his client believed the medication had affected him.
That statement is a defence claim, not a medical or judicial finding. There has been no determination that Ozempic caused or contributed to the alleged killing, and the mere fact that a person was taking a prescription medicine does not establish a causal link to alleged criminal conduct.
Ozempic is the brand name for semaglutide, a GLP-1 receptor agonist used in the treatment of type 2 diabetes and also widely discussed in relation to weight management. Questions about possible side effects in an individual case are matters for qualified clinicians and, where relevant, expert evidence. They cannot be resolved from a lawyer’s statement in an initial court appearance.
The distinction is particularly important in a murder case because several separate issues can arise. One concerns whether prosecutors can prove the physical acts alleged. Another concerns the accused person’s state of mind at the relevant time. A third, if raised, can involve whether a mental-health condition affects criminal responsibility or a person’s fitness to participate in proceedings. Those questions are governed by evidence and legal tests, not by assumptions based on a diagnosis or medication history.
Mr Faiz reportedly sought an assessment and raised the possibility of his client being transferred to a mental-health facility. Police did not oppose access to a psychologist but opposed a transfer at that stage. No bail application was made, and bail was formally refused.
NSW Police have publicly confirmed only the core charging facts: emergency services were called to the Bondi Beach unit, the 90-year-old woman was found with significant injuries, a 47-year-old man known to her was arrested, and he was later charged with murder.
More detailed allegations reported from the court hearing and other media accounts — including descriptions of the number of wounds and the sequence of events inside the unit — remain allegations that have not been tested at trial. They should not be treated as established facts simply because they have appeared in early reporting.
The domestic violence classification of the charge reflects the family relationship between the accused and the deceased. It does not alter the prosecution’s obligation to prove the offence beyond reasonable doubt.
In New South Wales, the first court appearances in a serious indictable matter are largely procedural. The court does not decide guilt at that stage. Questions such as bail, legal representation, medical assessment and the timetable for service of the prosecution brief can be dealt with while the evidence is assembled.
That process also gives both sides time to obtain material that cannot be produced immediately after an arrest. Police may be waiting for forensic results, pathology evidence, witness statements or analysis of electronic devices. A defence team may seek medical records, expert reports and information about the accused person’s treatment history.
Those later documents are more important to any argument about mental health or medication than comments made in the first hours of a case. Until expert evidence is available, claims about what caused a person’s behaviour remain untested propositions rather than established explanations.
Ms Spivak’s death occurred during a period in which NSW authorities were responding to several unrelated deaths involving women and alleged violence by people known to them. That broader context has renewed public discussion about domestic and family violence, but each case has its own facts and legal process.
For Ms Spivak’s family and neighbours, the criminal case is also unfolding alongside grief. Residents have described her in media reports as a quiet and well-liked elderly woman. Those personal accounts sit apart from the legal questions the court must now determine.
What happens next
Mr Mitnik is due to appear in Downing Centre Local Court on September 24. At that stage, the court may deal with procedural matters including the progress of the police brief, future hearing dates and any applications relating to medical assessment or custody arrangements.
A murder prosecution generally develops over months rather than days. Investigators can continue collecting forensic material, witness statements, electronic evidence and medical information after a charge has been laid. Prosecutors then assess the evidence that will form the case, while the defence can obtain its own expert material where appropriate.
If Mr Mitnik’s lawyers intend to rely on mental-health evidence, the nature and legal significance of that evidence will need to be established through the court process. It would be premature to assume what argument, if any, will ultimately be made or accepted.
The same caution applies to the reference to Ozempic. There is public interest in GLP-1 medicines because of their rapid growth in use, but the court has not been presented with any finding that the drug caused the alleged offence. Any attempt to connect a medication with criminal responsibility would require evidence specific to the accused, including his health history, prescription details and expert opinion.
For readers following the case, the key verified position is therefore narrower than some headlines may suggest: Mr Mitnik has been charged with the domestic violence-related murder of his grandmother; his lawyer has raised mental-health concerns and said Mr Mitnik believes Ozempic affected him; and those claims have not been adjudicated.
Police inquiries remain ongoing. Anyone with information relevant to the incident has been asked to contact Crime Stoppers.
The September 24 appearance is unlikely to resolve the substantive allegations. Its importance is procedural: it can show whether the matter is moving towards service of a brief, whether the defence is seeking further medical material and what timetable the court sets for the next stage. Any later change in the charge or defence position should be reported from court records rather than inferred from the initial hearing.
If you or someone you know is experiencing family or domestic violence, 1800RESPECT provides support on 1800 737 732. In an emergency, call Triple Zero.