Cross-examination is an art-form with its own canons and principles. Asking questions is a simple matter. You can take a man off the street, put a gown on his back, send him into court and he could ask questions all day. The trick is to ask the right question in accordance with the golden rule, ‘If you don’t know the answer, don’t ask the question.’ When a witness is being co-operative and supplying all the right answers, the temptation is to push too far and ask one question too many thereby destroying all the previous good work at one fell swoop. The art lies in knowing when to stop or when to ask no questions at all.

Accused persons sitting in the dock expect their lawyers to be constantly on their feet, tearing into witnesses. In reality, the able lawyer aims to spend as much time as possible sitting on his backside. As a lawyer, when you are on your feet your client is in trouble. When you are seated, it means there is nothing to worry about.

Muirhead would normally begin by stroking a witness gently, teasing out such information as he could. Gradually he would turn the screw. Only if necessary would he resort to the mailed fist.

He began by asking Potter a number of general questions about her background. His tone was pleasant, affable, as if he was apologising for troubling her. He could see the girl begin to relax.

‘You have identified the accused, my client, as being someone who was at your place of work when you were offered this bribe?’

‘Yes.’

‘It will be clear to the members of the jury that you were doing your best to tell the truth. Would that be fair?’

‘I hope so.’

‘Of course. Of course. And no doubt you told us the truth about the reasons for and the nature of your encounter with Kevin Boyle?’

‘Yes. Certainly.’

‘And presumably the jury should have no difficulty in accepting that they heard from you the whole truth?’

‘They should.’

This was easy, Potter thought. This man was clearly on her side. It did not dawn on her to ask why. She dropped her guard.

‘Then why are you lying?’

‘What?’

‘It’s a very simple question – why are you lying ?’

‘I’m not. What about?’

‘Who is Sharon McColl?’

‘I don’t know.’

Now it was not only her legs which were shaking – her whole body was shaking.

‘You know no one called Sharon McColl?’

‘I don’t think so.’

‘What do you mean, you don’t think so? Do you – yes or no?’

‘No…I can’t remember.’

The fifteen jurors sat forward expectantly. They knew something was about to happen. They were anxious to see what. The Crown team thought they knew what was coming as they had a statement from Sharon McColl. They too were in for a surprise.