In this special Age of Extinction mini-series from Science Weekly, which first aired in 2023, the Guardian’s biodiversity reporter, Phoebe Weston, explores the illegal killing of birds of prey on grouse moors, and asks why it is so difficult to solve these crimes. In the third and final episode, Phoebe finds out more about the pressures that drive people to commit raptor persecution, discovers how the police investigation into the case of Susie’s crushed chicks unfolded, and how Susie, the hen harrier, is doing now. Help support our independent journalism at theguardian.com/sciencepod