Where is Caroline Muirhead now? The true story behind Netflix's 'Should I Marry a Murderer?'

Netflix’s latest documentary true crime offering, Should I Marry a Murderer? has had viewers gripped and soared straight in to the UK's top spot on the streaming service.

The three-part docuseries follows the unimaginable pain and dilemma that Dr Caroline Muirhead, a pathologist who thought she’d found her happily ever after on a dating app, was confronted with – after learning that her fiancé was hiding a truly horrific secret. Should I Marry a Murderer? features personal footage from Muirhead's phone, detailing her relationship with Alexander 'Sandy' McKellar, and his brother, Robert.

Here is everything you need to know about Dr Caroline Muirhead, the tragic case of Tony Parsons, and where the brave fiancée-turned-witness is today.

Dr Caroline Muirhead is a Scottish forensic pathologist whose life changed forever after a fateful swipe right. In September 2020, she matched with Highland gamekeeper, Alexander 'Sandy' McKellar on a dating app and quickly started spending most weekends at his country estate.

Their whirlwind romance, fuelled by alcohol, shooting afternoons and, in Muirhead's eyes now, her vulnerabilities, soon lead to the pair getting engaged (much to the dismay of many of Muirhead's friends).

Muirhead described feeling "accepted, wanted, seen" by her new partner Sandy McKellar, following a previous upsetting relationship experience, and was blissfully unaware of his dark past.

But a couple of months into their relationship and shortly after McKellar proposed, Muirhead asked him a question that would blow her world wide open: was there anything in his past that could affect their future? It was then that McKellar dropped a devastating bombshell, confessing to his involvement in a fatal, covered-up hit-and-run – and even then, only telling Muirhead the partial truth.

Caroline and Alexander

In September 2017, Alexander McKellar and his twin brother Robert were driving along the A82 in Argyll, Scotland, after drinking at a local pub with a shooting party. Their vehicle struck and killed 63-year-old cyclist Tony Parsons. Tragically, Parsons – who was a retired Royal Navy officer, grandfather, and cancer survivor – was cycling a 100-mile route in aid of a prostate cancer charity at the time.

Instead of calling for help, the McKellar brothers went to horrific lengths to hide what they’d done. They swapped vehicles, returned to collect Parsons and his bike, and buried his body in a bog used for dead animals on the 9,000-acre Auch Estate where they lived and worked. For three years, Parsons' family had no idea what had happened to him.

When initially confession to Muirhead, McKellar said that Parsons had died instantly – but she later found out via his brother that there was more to the sick story.

After the confession, Muirhead was faced with the ultimate unthinkable dilemma: stay loyal to the man she loved, or risk everything to expose the truth. Choosing to do the right thing for Parsons and his family over her future marriage, Muirhead went undercover to gain more information from McKellar.

She bravely coaxed McKellar into taking her to the makeshift grave, where she secretly marked the exact spot by stamping a Red Bull can into the ground. She then tipped off Police Scotland, working as a covert witness over several gruelling months to gather evidence that led to the brothers’ arrest in December 2020.

In August 2023, Alexander McKellar was sentenced to 12 years in prison for culpable homicide and attempting to pervert the course of justice. His brother, Robert, received a five-year sentence for his role in the cover-up.

After successfully bringing her former fiancé to justice, Dr Caroline Muirhead stayed out of the public eye to process the immense trauma of her ordeal. She explains she has "no regrets about coming forward" and has since moved to the coast, in order to "move forward" with her life.

Muirhead now has a new partner and says she has regularly been seeing a psychiatrist. She has also shared that she has gone sober, focussing on a quieter, calmer pace of living.

"I've got a much better relationship with my family," she adds. "I met someone new, who is incredibly kind. When you love yourself, you will attract healthy love."

After a five year investigation, most of Muirhead's complaints against Police Scotland (which included alleging that they did not offer her adequate support after she had reported McKellar's crimes) were largely not upheld.

Should I Marry a Murderer? was released globally on Netflix on 29 April 2026.