‘Make sure you all read the reports,' Tailby was saying. 'But I'll sum up the main points. Late this afternoon a witness came forward. A gentleman by the name of Gary Edwards. Mr Edwards is a bird-watcher. On Saturday evening, he was positioned on the top of Raven's Side on the north of the valley at Moorhay. He was, it seems, watching for pied flycatchers, which are a rare species known to breed in this area. Mr Edwards had travelled from Leicester purely on the chance of seeing a pied flycatcher, so that he could tick it off on a list of British species. I'm told this activity is called twitching.’

Cooper saw some of the officers smiling, but he knew Tailby wasn't joking. It was very rare that he did. The DCI looked up at them over his reading glasses, then back down again at the report in his hands.

‘Mr Edwards thought the oak and birch woodland near the stream was a likely site. At one stage, though, he says he was watching a pair of merlins nesting on the cliff face below him. While he was doing this, his attention was taken by a bird flying towards the woodland, which he felt might be the said pied flycatcher. He followed the flight of this bird with his binoculars.’

In Cooper's hands was a summary of interviews conducted with Graham and Charlotte Vernon, and with Molly Sherratt, as well as with the bird-watcher. Some of the details were marked as new information, and would be followed up with actions the next day. There were also reports of the attempts made by DI Hitchens's team to trace Lee Sherratt, without success. From the tone of the summary, Cooper was left in no doubt that Sherratt was considered the obvious suspect. All they had to do, it was inferred, was to find Sherratt and let the forensic evidence establish his guilt. The rest was all for show.

‘It should be stated at this point,' said Tailby, 'that Mr Edwards was equipped with a pair of Zeiss roof-prismtype binoculars with a magnification of x 10 and a 45 mm diameter object lens. A powerful bit of kit. He says he trained these binoculars on the area of woodland into which the bird had disappeared, and he waited to see if there was any further movement. There was. But it wasn't a bird.’

Tailby paused, like an actor savouring the effect, trying to get his timing just right.

‘Mr Edwards further states that he followed a movement in the undergrowth of something black, only to find the head of a dog appearing in his view. Due to the small field of vision of binoculars of that power, he took them away from his face and with unaided vision saw a man with a dog. We believe from Mr Edwards's statement that this was near the spot where Laura Vernon was found. The time: approximately seven-fifteen.’

There was a little stir of excitement. The bird-watcher had been in position within an hour of the incident, on a good vantage point, with a powerful pair of binoculars.

Who could ask for anything better? What more had the twitcher seen? Cooper observed that Fry had been scribbling notes rapidly, turning over the page with the spiders and turning again. Now she was sitting bolt upright, alert and eager. He could see that she was getting ready to take the first opportunity to put in a question, to make sure she was noticed.

‘Unfortunately for us,' said Tailby, 'Mr Edwards then completely lost interest in the area of woodland. He reasoned that the human and canine presence would disturb the bird population. Particularly the pied flycatcher, which is of a somewhat secretive and sensitive nature, apparently. His attention returned to the merlins. Mr Edwards then remained on Raven's Side until nine-thirty approximately, but he saw nothing further of interest to us.’

Fry stirred. 'Over two hours, sir? What was he doing all that time?'

‘Yes. DC Fry, isn't it? That is a question that was put to him, Fry. He states that he was waiting for dusk on the chance of observing little owls hunting.'

‘Tell him to get a life,' said someone from the back.

‘I don't need to point out that this could be an absolutely vital witness,' said Tailby, ignoring the interruption.

Ben Cooper raised a hand. 'The man with the dog, sir. Are we thinking it was Harry Dickinson? According to Dickinson's statement, he walks in that area regularly.'

‘Unfortunately, Mr Edwards wasn't able to give us a description. He was too far away, and did not study the man through his binoculars.’

There were general sighs of disappointment.

‘More interested in pied flycatchers than people,' said the same voice.

‘However, Mr Dickinson will be spoken to again today,' said Tailby. 'In the initial interview he was not asked about Saturday evening. It may be that he was on the Baulk at that time and he saw something useful. Mr Dickinson will be among the actions for the morning.'

‘It would be a bit of a coincidence, wouldn't it, sir?’

‘How so, Cooper?'

‘I mean, Dickinson being in the area at the time Laura Vernon was killed and maybe seeing the murderer. And two days later being in the same area and finding the trainer which led us to her body. That's what we're saying here, isn't it? A bit of a coincidence, surely.'

‘What would be your interpretation, Cooper?'

‘I think we ought to press Harry Dickinson harder.’

Tailby frowned. 'At the moment we are not considering him as a suspect, merely a potentially useful witness.'

‘But if —'

‘Now,' said Tailby, turning away, 'we have to look at the immediate family. Obviously, we need to bear in mind the possibility of a family row of some kind. The parents have to be under suspicion.' Tailby waited for somebody to ask him why. No one did. But he told them anyway. 'Murders occur mostly within families. The statistics tell us this.’

All the faces in the room continued to look at him expectantly.

‘For that reason, we will be looking more closely at the Vernons. Particularly the relationship between Laura Vernon and her father. I have spoken to Graham Vernon myself, and I have to tell you I'm not happy in that respect.'

‘Haven't we got a TV appeal lined up with him, sir?'

‘Yes, with both parents, in fact. That's scheduled for the morning. We will, of course, be watching them closely during the appeal.’

Cooper saw Fry nodding calmly, as if it was perfectly normal to suspect parents of murdering their own daughter. He wondered what cases she had worked on in the past to feel like that, or whether it was as a result of experiences in her own family. The thought made him feel very sad. His own family had been a totally happy one, and he thought the destruction of a family was the worst thing that could happen to anyone.

And then there's the brother,' Tailby was saying. 'Daniel Vernon. Nineteen years old and a student at Exeter University. We're led to believe that he was away in Exeter at the time that Laura went missing, and has only now arrived back in Moorhay. But we checked, and his term doesn't start for another two weeks. So what has he been doing? I need his movements tracing — when did he leave and how did he get back? From a brief look at him earlier this afternoon, I'd say he was a pretty angry young man. On the other hand, you don't need me to tell you that the victim's family must be treated with care. I don't want any complaints about officers being heavy-handed or insensitive.’

The DCI paused to allow this to sink in, then turned to gesture at an impressive aerial photograph of Moorhay, taken by the helicopter crew and blown up to enable the probable route of Laura Vernon's last journey to be superimposed on to it.

‘Meanwhile, I intend to begin a full search of the Vernons' garden,' he said. 'This is in view of the possibility that Laura may have met someone there shortly before she was killed. Remember the sighting of her talking to a young man earlier in the evening. We need to find evidence to establish the identity of that young man. It is, however, a very large garden.’