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.…