Detectives want to trace all taxi driver Steve Johnson 's passengers in Stoke-on-Trent on the evening of Friday 21 December. One of them decided to kill him. Perhaps you were shopping in Cheltenham on Wednesday 30 January? If so, you may have seen a gunman and his accomplice. And Maria Requina from Manchester was murdered only weeks after talking on TV about the dangers of street life.

Alan Leppard had spent Easter Monday happily at home with his girlfriend in the quiet village of Monkton, Kent. That night he was shot dead on his own doorstep. Could you have seen his killers in a large American car?