Alexander McKellar — also known as Sandy McKellar — is currently serving a 12-year prison sentence in Scotland after pleading guilty to the culpable homicide of charity cyclist Tony Parsons. His case became the subject of the Netflix documentary Should I Marry a Murderer?, which premiered on 29 April 2026 and tells the extraordinary story of his fiancée, forensic pathologist Dr Caroline Muirhead, who gathered covert evidence against him while secretly working with Police Scotland.

Who Is Alexander McKellar?

Alexander “Sandy” McKellar was born in 1991 and grew up with his twin brother Robert on the Auch Estate, a remote farming and shooting property near Bridge of Orchy in the Scottish Highlands. The brothers worked the estate as farmers and gamekeepers. Sandy McKellar met Dr Caroline Muirhead — a forensic pathologist from Edinburgh — through the dating app Tinder in 2019, and the couple became engaged in 2020.

By the time he proposed to Muirhead, McKellar was already carrying the secret of what he and his brother had done to a charity cyclist they had struck with a vehicle on the A82 road in September 2017. It was only after Muirhead pressed him on a suspicious comment that McKellar made a full confession to her — a decision that would ultimately lead to his arrest, conviction, and imprisonment.

The Death of Cyclist Tony Parsons

Tony Parsons was a 63-year-old retired Royal Navy petty officer and prostate cancer survivor from Tillicoultry, Clackmannanshire. On the night of 29 September 2017, Parsons set out on a solo 104-mile overnight charity bike ride along the remote A82 through the Scottish Highlands. He was last seen alive at the Bridge of Orchy Hotel at around 11:30 pm, where he stopped for coffee before continuing south.

He never arrived home. Parsons’ disappearance prompted a major Police Scotland missing persons investigation, but for more than three years his fate remained unknown. He became known in Scottish media as the “Vanishing Cyclist.” His widow and family faced years of agonising uncertainty about what had happened to him.

In reality, Alexander McKellar had struck Parsons with a vehicle on the A82 near Bridge of Orchy. The brothers then concealed the body in a boggy area on the Auch Estate rather than reporting the incident to the police. Tony Parsons’s remains lay hidden on the estate for over three years.

How Caroline Muirhead Exposed Him

In 2020, shortly after McKellar proposed to her, he made a confession. Muirhead, drawing on her professional background in forensic pathology, immediately understood the gravity of what he was describing. Rather than confronting McKellar directly or walking away, she made the remarkable decision to remain engaged to him while covertly gathering evidence to hand to police.

Over the following months, Muirhead worked closely with Police Scotland detectives. One of the most significant pieces of evidence she obtained was a Red Bull can she strategically left near the concealed grave site on the Auch Estate, enabling investigators to locate Tony Parsons’s remains. Her courage and methodical approach turned what might have remained a cold case into a successful prosecution.

Parsons’s body was recovered in 2020, and both McKellar brothers were arrested. Muirhead’s role as a key witness against her own fiancé was pivotal in securing their convictions. She has since spoken publicly about the emotional toll of the experience and her desire to ensure justice for Tony Parsons and his family. If you have a loved one currently held on remand in Scotland, you can find guidance on booking a prison visit on our site.

Trial, Conviction and Prison Sentence

At the High Court in Glasgow on 26 July 2023, Alexander McKellar pleaded guilty to culpable homicide and attempting to defeat the ends of justice. On 25 August 2023, Lord Armstrong sentenced him to 12 years in prison. Because McKellar had been held in custody since his arrest in 2020, the sentence was backdated accordingly — meaning he had approximately six years remaining as of his sentencing date. He becomes eligible to be considered for parole in approximately late 2027, though release is not guaranteed.

As of April 2026, Alexander McKellar remains in custody in a Scottish prison. The Scottish Prison Service does not routinely disclose which specific establishment an individual is held in, but McKellar is serving his sentence within the Scottish prison estate. For information on how the UK parole process works, our guide explains eligibility criteria in detail.

What Happened to Robert McKellar?

Robert McKellar — Alexander’s twin brother — pleaded guilty at the same hearing on 26 July 2023 to attempting to defeat the ends of justice, specifically for his role in helping conceal Tony Parsons’s body on the estate. Lord Armstrong sentenced Robert to five years and three months in prison. Unlike Alexander, Robert was not charged with culpable homicide, as prosecutors accepted that Alexander was the driver at the time of the collision.

Given the backdating of Robert’s sentence to the point of his arrest, and the standard Scottish early-release provisions, it is likely that Robert McKellar has now completed his custodial sentence or is approaching the end of it. His current status and whereabouts are not publicly confirmed. If you need to send money to a prisoner in Scotland or elsewhere in the UK, our guide explains how the process works.

The Netflix Documentary (2026)

The two-part Netflix documentary series Should I Marry a Murderer? premiered on 29 April 2026. The series focuses primarily on Caroline Muirhead’s account — her relationship with Sandy McKellar, the confession, her decision to assist police, and the emotional aftermath. It also provides extensive coverage of the original investigation into Tony Parsons’s disappearance and the eventual recovery of his remains.

The documentary has drawn significant public interest in the UK, with viewers searching for information about where Alexander McKellar is currently held, when he might be eligible for parole, and what became of Caroline Muirhead. Muirhead has spoken in interviews about the enormous personal cost of her decision to work covertly with police, and she has expressed a commitment to advocating for victims of serious crime.

The case raises broader questions about culpable homicide sentencing in Scotland, the role of civilian witnesses in cold cases, and the psychological impact on those who discover that someone they love has committed a serious crime. It is a rare and striking example of a potential victim — Muirhead herself — choosing to place justice above personal interests in exceptionally difficult circumstances.

Frequently Asked Questions

Is Alexander McKellar still in prison?

Yes. As of April 2026, Alexander McKellar remains in custody in a Scottish prison. He was sentenced to 12 years in August 2023 after pleading guilty to culpable homicide and attempting to defeat the ends of justice. He is not eligible for parole consideration until approximately late 2027 at the earliest.

Which prison is Alexander McKellar in?

The Scottish Prison Service does not publicly disclose the specific establishment where individual inmates are held. Alexander McKellar is serving his sentence within the Scottish prison estate. If you need to locate a prisoner in Scotland, you can contact the Scottish Prison Service directly or use official prisoner tracing procedures.

When will Alexander McKellar be released?

Alexander McKellar received a 12-year sentence backdated to his 2020 arrest. Under standard Scottish parole rules, he becomes eligible to be considered for release on parole at approximately the halfway point of his sentence. This means parole eligibility falls around late 2026 or early 2027, though any release decision is at the discretion of the Parole Board for Scotland and is not automatic.

What was Alexander McKellar convicted of?

Alexander McKellar pleaded guilty at the High Court in Glasgow in July 2023 to two charges: culpable homicide (the Scottish equivalent of manslaughter) in connection with the death of cyclist Tony Parsons, and attempting to defeat the ends of justice by concealing Parsons’s body on the Auch Estate in the Scottish Highlands. He was sentenced in August 2023.

What happened to Robert McKellar after prison?

Robert McKellar was sentenced to five years and three months in prison in August 2023 for attempting to defeat the ends of justice. Given that his sentence was backdated to his arrest in 2020, it is likely that Robert has now completed or is nearing the end of his custodial sentence. His current whereabouts are not publicly confirmed. He was not convicted of culpable homicide, as he was not the driver at the time Tony Parsons was struck.