Metropolitan Police Commissioner Dame Cressida Dick pays tribute to SergeantMatt Ratana, who died after being shot at Croydon Custody Centre.
Thecommissioner was at a National Police Memorial Day wreath-laying in St James'sPark, London.
Man arrested on suspicion of murdering police officer Matt Ratana
PA - Press Association STUDIO
A 23-year-old man has been arrested on suspicion of murdering MetropolitanPolice Sergeant Matt Ratana. Metropolitan Police..
