I was reading Alastair MacLean’s book, The Satan Bug, and in it the protagonist finds a stack of £5 notes apparently used as a payoff. He mentions that the notes can be traced. In another book (name eludes me), I saw the same thing mentioned.
The Satan Bug is an older book from the 60s. Could the British Police back then somehow trace £5 notes? How? Why are £5 notes special in this regard?
All Sterling notes have a unique serial number, so if it’s a large stack used as a payoff then it might be a large bundle of consecutively numbered notes*. Potentially those numbers could be flagged so that a notification is made whenever one passes through a bank. That would glean at least some information for the police.
The £5 thing is likely just a product of the times - the largest commonly used note back then. Nowadays, that would most likely be the £20 note.
Now that’s interesting. Had no idea.
£5 in 1960 would be equal to £100 now.
The extent which higher denomination notes could be traced is surprising, one important clue that was missed in the hunt for the Yorkshire Ripper was that Peter Sutcliffe had used a £5 note to pay a sex worker, and after he had murdered her he had forgotten he left it on her.
He tried to return to the body to retrieve I, however he still didn’t discover the note, but when police discovered the body, they did a thorough search of the area and found it.
Turns out that the note could be traced to the payroll of the company that employed Peter Sutcliffe, and that would have hugely narrowed the search.
The capacity of the serial number to lead to Sutcliffe is, I fear, hindsight wisdom. It is useful to confirm Sutcliffe but not to find him. It assumes that the note’s use in paying the prostitute was the first use of it after it was paid to someone at Sutcliffe’s workplace. If it had passed through even one set of hands before getting to the prostitute, there is an exponential explosion in the number of random and unidentifiable people it might be. Sadly a serial number does not tell you how many times the note has been spent.
The problem does not arise in reverse, however. If you have good evidence of Sutcliffe’s involvement, the note adds to general strength of the case because of Occam’s Razor.