W hen pathologist Caroline Muirhead said yes to her boyfriend’s proposal after just a few months of dating, she couldn’t believe her luck. Her elation soon turned to horror when the man in question, Alexander “Sandy” McKellar, shared a secret he’d kept for years – that he had killed a cyclist and buried him with the help of his twin brother. In 2023, Scottish brothers Alexander and Robert McKellar were convicted in relation to the death of Tony Parsons, who had disappeared while cycling between Scotland’s Bridge of Orchy and Tyndrum six years earlier. Alexander McKellar pled guilty to culpable homicide and attempting to pervert the course of justice after hitting Parsons with his car, leaving him to die and eventually burying him under the hunting estate that he worked on. However, for a long time, he wasn’t aware that it was his fiancée, Muirhead, who played a major role in his arrest.…