‘He died yesterday evening, but –’ Geraldine hesitated, unsure how much to reveal at this stage.

‘Well, there you go then. I was here all evening. You can check our security cameras if you don’t want to take my word for it. My mother insisted we had them installed all round the house. My father paid for it all,’ she added with a shrug, as if to say she thought it an unnecessary expense.

Geraldine nodded and thanked her for her help. Her claim to have been at home all evening could be a deliberate deception, as could her apparent ignorance of the way David had been killed. The suggestion that the police check the security camera might be a bluff. In any case, Jessica could have slipped out of the back door of the house and walked crouching down to avoid the camera. All the same, she arranged for the camera to be removed so the film could be examined.

Driving back to the police station, Geraldine thought about how Jessica had spoken, as though being at home alone was something difficult. Although Geraldine had never struggled with her own company, having lived with Ian for only a few months, she no longer wanted to be on her own. But she was too busy to have time to worry about her own circumstances. That afternoon, Eileen had summoned the team together to discuss the toxicology report. The findings at the post mortem had already established that the threat to David’s life had been serious.

‘The victim was drugged before he was suffocated,’ Eileen reminded them.

‘It wouldn’t have been difficult to give him the pills without his knowing. He then drank a couple of glasses of whisky on top of that before going out, intending to drive, if Anne is telling the truth,’ Geraldine said.

‘He could have taken the pills himself,’ Eileen pointed out. ‘He certainly knew he was drinking.’

‘Are you saying you think he was intending to kill himself before he was murdered?’ Ariadne asked.

Eileen shrugged. ‘That’s what we’re going to find out. All we know right now is that he swallowed some chemical combination that caused him to fall unconscious and choke, before someone came along and took the opportunity to finish him off.’

‘Did SOCOs find any evidence of cetirizine in the house?’ Ian asked.

‘The house hasn’t been searched yet. I daresay we’ll find them, but that won’t prove anything. Even if he bought them himself, his wife might have handled the bottle. They are a common treatment for allergy relief, and he could have asked her to buy them, or to fetch the bottle for him,’ Geraldine replied.

‘What about the letter?’ the detective chief inspector asked. ‘Only David and Anne’s prints were found on it so the writer was careful to avoid touching it with his bare hands.’

‘Or her hands,’ Ariadne added. ‘His daughter described him as a bully.’