Two months after Elizabeth McCormack complained to police that her ex-boyfriend had raped her, she was found brutally murdered. Police attempts to charge chief suspect John Omokhoje foundered because of lack of evidence. It became a long and complicated battle of wits, which ended when police got a lucky break.

Nearly five years ago, young vagrant David Paterson was shot and seriously wounded as he chased an armed robber. Today, he is still in hospital - partly-paralysed and receiving round-the-clock care. Tonight's programme looks at the police investigation which led to the jailing of the gunman.