Christopher Halliwell was a taxi driver from Swindon, Wiltshire, England. Born in 1964, he led a seemingly ordinary life, working as a cab driver and raising a family. However, beneath this facade, Halliwell harbored dark tendencies that would later come to light. He was known to be meticulous and had a keen interest in fishing, often frequenting secluded areas—knowledge that would later aid in concealing his crimes.

On March 19, 2011, 22-year-old Sian O'Callaghan disappeared after leaving a nightclub in Swindon. Her disappearance prompted a massive search operation. 

Using mobile phone data, police traced her last known location to the Savernake Forest area. On March 24, 2011, Halliwell was arrested at an Asda supermarket in Swindon. During interrogation, he confessed to murdering O'Callaghan and led police to her body near Uffington, Oxfordshire. He also revealed the location of another victim, Becky Godden-Edwards, who had been missing since 2003.

However, due to procedural errors during the initial investigation—specifically, the failure to caution Halliwell and provide legal representation—his confession regarding Godden-Edwards was deemed inadmissible in court. Despite this, new evidence emerged, and on September 19, 2016, Halliwell was convicted of Godden-Edwards' murder and received a whole life order, ensuring he would spend the rest of his life in prison without the possibility of parole.