The families of Barnaby Webber, Grace O'Malley-Kumar and Ian Coates were assured by the PM that a 'number of different agencies' would be scrutinised by the probe.
Valdo Calocane killed 19-year-old students Barnaby Webber and Grace O'Malley-Kumar and 65-year-old caretaker Ian Coates before attempting to kill three other people in June 2023.