Catching a Killer: Season 1, Episode 4

1 - 4: A Knock at the Door

At 6pm on 31 January 2017, three days after Chinese New Year, 64-year-old Hang Yin Leung hears a knock at the door. She's alone at home and not expecting any visitors. Her husband works seven days a week at the takeaway business they've built together. She answers the door and, within seconds, the lives of this hard-working family are changed forever. A violent attack by six men leaves the house ransacked. They are heard laughing as they run off down the road with bags of stolen goods and the family savings. But the worst is yet to come: as Hang Yin reveals to police the true nature of the attack, she falls ill and is rushed to hospital. She never recovers. Her death launches a huge cross-border manhunt and one of 'the most difficult homicides' the detectives have ever investigated.