A File on 4 special documentary.
Four men accused of attempted murder in a machete attack were found not guilty last year, after their alleged victim told the court that his horrific injuries might have happened in a car crash. Two men accused of murder were acquitted when a teenage girl who was the main witness to the shooting went into hiding and took an overdose, rather than be identified in court. Gerry Northam examines a number of recent trials where vital witnesses complained of intimidation and were frightened to give evidence openly. Producer Ingrid Kelly