Stephen McCullagh has been convicted of the murder of Natalie McNally at Belfast Crown Court, in a case centred on the use of a fabricated digital alibi involving a pre-recorded YouTube livestream.
The jury returned a unanimous guilty verdict, triggering a mandatory life sentence, with the minimum tariff to be set at a later hearing.
The case highlights how UK courts assess false alibis, digital evidence, and intent in serious criminal prosecutions.
Natalie McNally, who was killed in Co Armagh in December 2022, in a case where a false digital alibi led to the conviction of Stephen McCullagh.
Murder Charge and Legal Threshold
Under Northern Ireland law, a conviction for murder requires proof that the defendant unlawfully killed another person with the intention of causing death or serious harm.
This element of intent, often referred to as mens rea—must be established beyond reasonable doubt.
In this case, the prosecution relied on a combination of digital forensic evidence, CCTV material, and witness testimony to argue that the killing was both deliberate and premeditated.
How the False Alibi Was Uncovered
Natalie McNally, 32, who was 15 weeks pregnant, was killed at her home in Co Armagh in December 2022.
At trial, prosecutors alleged that Stephen McCullagh created a pre-recorded YouTube livestream to simulate real-time activity, before leaving his home and travelling to the victim’s address.
Evidence showed that the victim accessed the stream shortly before the attack, while CCTV tracked a man matching the defendant’s description travelling between locations during the relevant period.
Following the incident, McCullagh contacted others and emergency services, and later suggested that an alternative individual may have been responsible.
The prosecution case centred on the disconnect between digital activity and physical movement.
Forensic analysis of the defendant’s devices revealed no real-time interaction during the supposed livestream, supporting the conclusion that the broadcast had been pre-recorded.
Witness testimony further supported the prosecution’s case. One witness described the defendant as “manipulative” and “calculated,” while outlining his behaviour following the incident.
Prosecutors argued that the construction of the alibi required prior preparation, inviting the jury to infer planning and premeditation.
Taken together, this evidence enabled the jury to reconstruct the timeline of events and ultimately return a unanimous guilty verdict.
Legal Process and Implications
The case progressed through the standard criminal process in Northern Ireland, beginning with a police investigation that included detailed digital forensic analysis.
Following arrest and interview, it proceeded to a jury trial at Belfast Crown Court, where a unanimous guilty verdict was returned.
A conviction for murder carries a mandatory life sentence, with the court required to set a minimum tariff at a later hearing before any consideration of parole.
The case underscores the growing role of digital evidence in criminal prosecutions.
While online activity may be relied upon to support an alibi, it is subject to forensic scrutiny, including analysis of timestamps, metadata, and user interaction.
Where such material is shown to be fabricated, it may significantly undermine a defence.
Although a false alibi is not itself a standalone offence in this context, courts may treat deliberate deception as evidence of consciousness of guilt and, in some cases, as indicative of planning or intent.
The case also reflects a broader evidential approach in which CCTV, device analysis, and witness testimony are combined to establish a coherent timeline capable of meeting the criminal standard of proof.
Sentencing and Next Steps
A conviction for murder carries a mandatory life sentence, with the court required to determine a minimum tariff at a future hearing.
In setting this tariff, the court will assess the seriousness of the offence, including any evidence of planning or premeditation, as well as relevant aggravating and mitigating factors.
Following the verdict, the victim’s family welcomed the outcome and thanked the public for their support, underscoring the broader human impact of the case and the role of the criminal justice system in delivering accountability.