On 31 January 2017, restaurant owner Hang Yin Leung, 64, was violently attacked as burglars ransacked her Milton Keynes home.
They fled, laughing, with the family’s savings and jewellery. But worse was to come.
As Hang gave her witness statement to the police the next day, she fell ill, was rushed to A&E and died.
It was now a murder inquiry. Filmed over a year, this documentary follows the investigation.