When Caroline Muirhead’s fiancé Alexander McKellar confessed to her in 2020 that he had killed a man years earlier in a hit-and-run, she couldn’t believe her ears. But instead of immediately breaking up with him, she used her proximity to bring him to justice.
In the new Netflix docuseries Should I Marry a Murderer?, Muirhead recounts how she gathered evidence against McKellar to help the police catch him and solve the cold case of missing cyclist Tony Parsons.
Here’s what you should know about McKellar’s chilling crime and confession.
Who Is Alexander McKellar?
Born and raised in Scotland, Alexander “Sandy” McKellar worked as a farmer alongside his twin brother, Robert, in the small village of Bridge of Orchy. He was also an avid hunter and was known for taking groups out to hunt deer in the Scottish Highlands.
After celebrating a successful hunt at a hotel bar in September 2017, things took a turn for the worse when he struck 63-year-old charity cyclist Tony Parsons with his car while driving under the influence of alcohol and left him to die.
A former Royal Navy officer and cancer survivor, Parsons was on a 100-mile solo bike ride for charity when McKellar hit him. He was not immediately killed upon impact, succumbing to his extensive injuries around 20 to 30 minutes after the accident.
Instead of calling for medical assistance, however, McKellar and his brother, who was in the passenger seat, left a still-alive Parsons to hide their damaged car. The pair later returned to hide his body, burying him in a shallow grave in a remote peat bog. They also destroyed his personal belongings and hid his bike behind a waterfall before later moving his body to a pit used for disposing of animal carcasses.
How Was Alexander McKellar Caught?
McKellar successfully kept the hit-and-run a secret for three years, but in 2020, he confessed the truth to his then-fiancée Caroline Muirhead, a forensic pathologist, who he had only been dating for a few months. The confession was prompted by Muirhead asking if there was anything she needed to know before they got married.
After sharing this shocking news, McKellar took her to the area where Parsons’s body was buried. While there, Muirhead secretly left a Red Bull can near the makeshift grave and later alerted the police.
McKellar and his brother had previously been questioned by police about Parsons’s disappearance but were not considered suspects—until Muirhead told the authorities where to find the body. They were arrested soon after in December 2020.
What Was Alexander McKellar Convicted Of?
The McKellar twins initially both pleaded not guilty to murder, but a month before their trial, they both took plea deals for lesser charges. In August 2023, Alexander was convicted of culpable homicide and attempting to defeat the ends of justice by the High Court of Glasgow and was sentenced to 12 years in prison. His brother Robert was sentenced to 5 years and 3 months for his role in concealing the crime.
“He is not an evil man. He acknowledges that he has done a terrible thing which has caused untold distress to the Parsons family,” Alexander’s lawyer, Brian McConnachie, said in court. “He would do anything he could to alter the decision he took in September 2017, but he cannot rewind the clock.”
In addition to the criminal charges, McKellar settled a civil case out of court in January 2025, in which his insurance company paid Parsons’s family a six-figure settlement. That August, the case was first explored on BBC Scotland’s true crime series Murder Case in a two-episode arc titled “The Vanishing Cyclist.”
Where Is Alexander McKellar Today?
Today, Alexander McKellar, 34, remains imprisoned in Scotland. Since his sentence was backdated to his 2020 arrest, he has around 6 years left to serve but could be eligible for parole as early as December 2027. His brother Robert, on the other hand, is likely a free man now, though his exact whereabouts are unknown.
How to Watch Should I Marry a Murderer?
Should I Marry a Murderer? explores McKellar’s hit-and-run through the perspective of Muirhead, who details how she set out to put him behind bars after he admitted to killing Parsons.
“It flips your entire world upside down,” Muirhead says of the confession in the trailer. “To remain in love, you have to keep this secret that you know is going to destroy you. But if you reveal it, then you destroy everything. I mean, what would you do?”
The two-part documentary series premieres on Netflix April 29.
Catherine Caruso joined the Biography.com staff in August 2024, having previously worked as a freelance journalist for several years. She is a graduate of Syracuse University, where she studied English literature. When she’s not working on a new story, you can find her reading, hitting the gym, or watching too much TV.
