Derek Wilcox was originally lined up for the run starting on 29 July 1982, but he told the court that owing to an unspecified 'very distressing occurrence', he did not feel up to it. When his boss at Poster Despatch and Storage asked him to do the trip he refused and was told to 'go home and not come back', he said.
As a result, the job was given to Robert Black, 46, of Stamford Hill, north London. The prosecution alleges that Mr Black snatched 11-year-old Susan Maxwell the next day as she walked home after playing tennis at the Scottish border town of Coldstream and subsequently murdered her.
Mr Black, 46, denies murdering Susan. He also denies murdering Caroline Hogg, 5, in July 1983, and Sarah Harper, 10, in March, 1986. He further denies kidnapping Teresa Thornhill, 15, in April 1988.
Caroline was seized at Portobello, near Edinburgh, Sarah at Morley near Leeds, and the attempt to drag Teresa into a van was made at Radford near Nottingham.
The prosecution has presented evidence setting out Mr Black's movements in an attempt to establish that he was in the areas where each girl was attacked and also where the three bodies were found.
The trial continues today.