'A hard watch': This 'devastating' Tony Parsons documentary came before Should I Marry a Murderer and it's free to stream
The 'fascinating' doc focuses on Tony Parsons and the investigation
Should I Marry a Murderer has captivated the world. Last year, the BBC tackled the “devastating” case in a documentary you can stream for free.
There are plenty of new documentaries coming this month, but it’ll be hard for Netflix to top Should I Marry a Murderer.
The series follows Caroline Muirhead, a Scottish doctor who discovered that her fiancé, Alexander “Sandy” McKellar, had killed and buried a man. She eventually reported him to the police, but she continued dating him, gathering evidence and struggling with all of her conflicting feelings.
It’s a compelling case. However, if it seems familiar, there’s a chance you may have watched this BBC documentary.
Should I Marry a Murderer fans need to watch The Vanishing Cyclist
Murder Case launched on BBC Scotland in 2019. As billed by the broadcaster, it takes a deep dive into “Scotland’s most complex and shocking murder investigations, with unprecedented access”.
It’s looked at several cases, such as the disappearance of Julie Reilly, a 47-year-old woman who was found to have been murdered, and Kiesha Donaghy, a mum-of-two who was killed in an “exceptionally savage, frenzied and brutal” murder.
Last year, in August 2025, the series released a two-part documentary: The Vanishing Cyclist.
If you’ve watched Should I Marry a Murderer, its name will make sense. Tony Parsons, the 63-year-old man killed by McKellar, had been on a solo charity bike ride when he was hit by their car in 2017.
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“As Tony embarked on his journey through the iconic Bridge of Orchy, he seemingly vanished without a trace,” the doc’s synopsis reads.
“Three years on, and one phone call changes everything. A woman has called 999 and revealed something truly astonishing: she knows the truth about what happened to Tony Parsons.”
This woman was Caroline Muirhead, McKellar’s fiancée, the main interviewee in Should I Marry a Murderer.
Bar a recording of her voice, Muirhead doesn’t feature in The Vanishing Cyclist. Instead, it focuses on the (controversial) police investigation and Parsons’ family and friends.
‘Reserve judgement until you watch The Vanishing Cyclist’
Whether it’s polarising reactions to Muirhead herself or the police’s treatment of her, Should I Marry a Murder has proven to be incredibly divisive.
That’s why viewers have recommended The Vanishing Cyclist. Not only is it an excellent, tightly put-together documentary in its own right, but it offers a wider perspective of the case that may leave you feeling differently about it all.
“The way she was portrayed in the BBC documentary by the police was absolutely abhorrent, they completely dismissed and downplayed her involvement with putting them on the path to solving it and how much danger she potentially was in from the brothers,” one viewer wrote.
“Seriously, anyone reading this needs to watch the BBC documentary and reserve judgement until afterwards,” they added.
“It was very harrowing, hopefully the family can move on,” another user wrote. “It was pretty awful and a hard watch,” a third commented.
“This was a fascinating watch – so glad his family finally got closure,” a fourth added.
“This is the true way how the story of how this happened, not like it was told from a different perspective and more of a film makeover like Netflix did,” a fifth argued.
How to watch Murder Case: The Vanishing Cyclist
Murder Case: The Vanishing Cyclist is available to stream on BBC iPlayer now.
You can also stream the rest of the Murder Case series for free.
Read more: The best movies you can watch on BBC iPlayer now
