But when Clare said she might detain him, pending analysis of the gun cartridge, his demeanour changed.

The solicitor raised a warning finger. ‘Perhaps, before we go any further, Mr Buchanan and I could have a private word.’

Five minutes later Clare and Chris resumed their seats and recommenced the interview.

‘Mr Buchanan has some information he would like to share with you,’ the solicitor said. ‘But we wish to make it clear he denies any wrongdoing. He is providing this information in order to exonerate himself.’

Clare smiled. ‘Of course.’ She turned back to Zac. ‘So, what is it you’d like to tell us?’

He shot a glance at Clare then looked away again, examining his fingernails. ‘I caught a bus,’ he said. ‘To St Andrews, like.’

‘Why?’

He shrugged. ‘Nice day and that. Fancied a walk on the beach. Mebbe an ice cream, ye ken?’ He glanced at his solicitor then said, ‘So I met a boy on the bus.’

‘Name?’

‘Abe. Abe McLeod.’

‘You knew Abe?’

‘Aye. Met him inside.’ He looked at Clare. ‘Bar-L, ye ken?’

Clare nodded. ‘Go on.’

‘So, Abe tells me he’s going up to St Andrews, too,’ Zac went on. ‘Said mebbe we could get a drink. Catch up ’n’ that.’

Clare decided to get to the point ‘Zac, was Abe in town to steal a car?’

Zac avoided her eye. ‘Might have been.’

‘And you went along to help him?’

He took a moment before answering. Then he said, ‘It’s no’ a crime to look, is it?’

‘No,’ Clare agreed. ‘But if it goes beyond that…’

Zac glanced at his solicitor. ‘Abe, he told me about this car. Said the owner had fallen behind on the payments. But he wouldn’t hand the keys back. Abe said he was supposed to go and get the car back. Said if I helped him he’d slip me a few quid.’

Clare suppressed a laugh. She had to hand it to Zac – full marks for imagination. ‘So, Abe told you he was legally entitled to repossess this car and asked you to assist. Is that correct?’

‘Aye.’ He avoided her eye.

‘In the middle of the night?’

Zac made no reply.

‘And did he show you paperwork relating to the repossession?’

He smiled at this. ‘Said it wasnae that kind of deal. The boy had bought the car off a lad Abe knows and hadn’t kept up the payments. Abe agreed to help the lad out.’

Clare sat back and folded her arms. She decided to keep Zac talking. Eventually he’d trip himself up. ‘What time was this?’

‘Bit after twelve.’

‘The early hours of Saturday morning?’

‘Aye.’

Chris said, ‘And, after you got into the car?’

Zac rubbed his chin. ‘Then I get this message.’

Chris raised an eyebrow. ‘Message? Like a text message? WhatsApp? Somebody pass you a note in the street?’

Zac threw him a look. ‘Text.’

‘From?’

He shrugged. ‘Didnae ken the number.’