The top sheets are statements from a joint NatWest account – Brian William Birch and Sheila Marie Birch – and unsurprisingly there are hundreds of transactions representing the minutiae of everyday life. In the debits he sees payments, among many others, to Asda, Costa Coffee, Total petrol, Domino’s Pizza, the National Lottery and Pets at Home. There are ATM withdrawals within the Chelmsford area and the usual utilities – Essex and Suffolk Water, British Gas – credit card payments and store-card bills. In the credits there are far fewer entries, mainly returns to stores and refunds, making it look as if Mrs Birch might be a keen shopper who loses interest in her purchases very quickly, and unshops on a regular basis. A sign, maybe, of a woman with too much time on her hands. What’s funding those purchases – apart from the credit cards – is what appear, without close scrutiny, to be regular credits from a company payroll, identical amounts month on month with Petersen Pneumatics Plc in the payee reference field.

Hagen grabs a yellow highlighter pen and marks a couple of these entries. Placing the sheets from the joint account to one side, he moves on to the next account, a NatWest current account in Brian Birch’s name only. For this account, there are only a couple of sheets, listing a few cash deposits – not huge amounts, but all four figures – and regular monthly payments made via standing order to his joint account with Sheila on the 28th of the month. The amounts of the payments tally exactly with what appear to be payroll credits in the joint account.

Hagen highlights these corresponding entries and stares at the sheets in front of him. Brian Birch is faking his salary. Why would he do that? In Hagen’s experience, the most common reason for that kind of deception is embarrassment over a job loss. Quite possibly, as Naylor suggested, Birch has been made redundant and daren’t tell his wife. But if he’s been made redundant and is no longer an employee of Petersen’s, who is he working for? He searches for the current balance on Birch’s personal account, and finds it a little over £8,000. That’s not someone who’s hurting for money – Hagen wishes his own account were only half as healthy – but it’s all coming from cash, and that’s a red flag. Generous deposits in cash are, as often as not, at least marginally suspect, signalling funds from a range of activities from tax evasion and illegal dumping of waste to drugs-peddling and people-trafficking. Where’s Birch on that spectrum? However he’s been making his daily bread, for some reason he doesn’t want his wife or the tax man to know about it.