Cambridgeshire Constabulary have sent him the crime report against Warren. He is feeling not so much disgust as a kind of blank bafflement. There is something in his head that just baulks at what he is reading – that a man could do that to his own daughter. He is reading the girl’s statement. It started when she was five years old. Five, he thinks. How is that possible? Thomas Warren and his wife divorced when the girl was eight, and she and her brother went to stay with their father every other weekend. After that it got much worse. The girl disclosed to her mother when she was eleven, but no action was taken. She developed an eating disorder and had a history of mental health problems, self-harm and so on, and dropped out of school when she was fifteen. There was a period in foster care. She had convictions for shoplifting and possession, a termination when she was seventeen. In her late twenties, it would seem she managed to turn things round for some reason and did some secretarial training and now works as a receptionist and admin assistant in a veterinary practice in Parnwell. At the age of thirty-one, she finally walked into Thorpe Wood Police Station and made a criminal complaint against her father.

After that, things got more complicated. Thomas Warren was questioned under caution. He denied the allegations, said he was shocked anyone could say such things about him and it was well known his daughter had had mental health problems her whole life. The mother was dead by then but the brother was interviewed and knew nothing about it.

Historic crime, Warren’s word against his daughter’s, no corroboration – it was all going to depend on how reliable she was as a witness and that wasn’t looking very good. There was her history of mental difficulties, the substance abuse. One Saturday night she had been arrested for drunk and disorderly – the officers had had to put a spit hood on her. In her initial statement, she got some key dates wrong, including the one when her father moved out of the family home, which was pretty essential. Thomas Warren had a steady employment history as a delivery driver. He paid his child maintenance regularly after the divorce. There were no other allegations against him. (At this point, Lockhart thinks, if it had been up to him, he would have wanted a good look at Warren’s computer, but you can’t do that without a search warrant and you don’t get one of those out of a magistrate unless he or she thinks there’s good reason.) The investigation stalled and if anyone involved had been asked at that stage, they probably would have said it was going nowhere.