
Former neonatal nurse Lucy Letby was convicted of murdering seven babies and attempting to kill seven others. Now, a new documentary – Lucy Letby: Who to Believe? – examines questions surrounding the trial, and it’s free to watch even if you’re outside the UK.
Letby first raised suspicion while working at the Countess of Chester Hospital, where a chief noticed an alarming surge in the deaths of premature babies between 2015 and 2016. What followed was an investigation that exposed the UK’s most prolific child serial killer in modern history.
She stood trial in 2022, pleading not guilty to seven counts of murder and multiple counts of attempted murder. Prosecutors argued that Letby deliberately harmed newborns in her care, using methods including injecting them with air or insulin.
Letby was sentenced to a rare whole life order in 2023, meaning she’ll never be released from prison. But after the verdict, debates have emerged over the evidence, media coverage, and trial, all of which are explored in the new true crime documentary.
How to watch new Lucy Letby documentary free
Lucy Letby: Who to Believe? is available to stream on BBC iPlayer now. Although the streaming service is geo-blocked for those outside the UK, you can overcome this barrier by using a VPN.
All you need to do is set your VPN to a UK location, create or sign into your BBC iPlayer account, and hit the play button.
You can use this same method to watch another Lucy Letby documentary that dropped earlier this month – Lucy Letby: Beyond Reasonable Doubt? – which similarly raises questions about the case.
Beyond Reasonable Doubt? can be watched for free on ITVX, the on-demand platform for the UK-based channel. To stream it, follow the same steps as you would for the BBC, except create or sign into an ITVX account instead.
What is Lucy Letby: Who to Believe? about?

The one-hour documentary goes beyond a simple retelling of events, weighing conflicting expert opinions and questioning how medical evidence was interpreted in court.
It’s important to understand that the circumstantial evidence against Letby is significant and overwhelming. However, her case has become part of a wider cultural debate about the UK’s justice and healthcare systems.
Supporters cite conflicting expert accounts as grounds for a retrial, while those who agree Letby is guilty see it as an open and shut case. This clash of perspectives is what’s explored in Who to Believe?
The official synopsis reads, “Lucy Letby was found guilty of unimaginable crimes – murdering seven babies and attempting to murder seven more. But her conviction has become one of the most divisive in British history.
“A panel of international experts says there’s no evidence any crimes were committed, while the police push for more charges against Letby and a public inquiry takes her guilt as a matter of fact.
“Both sides depend on complex medical evidence to explain how the babies died. Reporter Judith Moritz investigates the evidence and finds flaws in the theories presented by both prosecution and defence experts.”
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