I Spy With My Little Eye…
Using CCTV in your novel (Part 1)
This is the first in a three-part post looking at video surveillance and how it could be used in your books.
The articles will look at Closed Circuit TV (CCTV), Automatic Number Plate Recognition (ANPR) and dashcams, as well as more sophisticated applications such as night vision, body worn cameras and gait analysis. I will also highlight some of the myths perpetuated by TV and movies.
For brevity, I will usually just refer to it as CCTV, unless detailing a specific application.
Scale and History
The term Closed Circuit TV is simply a way of distinguishing between video that is broadcast widely and indiscriminately (eg television programmes) and video that is intended for ‘private’ viewing purposes and is not publicly available.
CCTV of some description has been available from as early as the late 1920s, when it was used to monitor the comings and goings of visitors to the Kremlin. In the 1940s, the Nazis used CCTV to remotely monitor the launch of V2 rockets. From the 60s, it was used as a precursor to pay-per-view services – for example broadcasting sporting events to paying audiences in select theatres.
Today it is widely used by governmental organisations, private companies and individuals for purposes ranging from security and law enforcement (criminal and terrorist activities), safety (monitoring motorways or public areas for accidents or potential accidents), efficiency (workforce monitoring, for example in factories and warehouses), evidence collection (police body-worn cameras or dashboard cameras) and deterrence (there is good evidence that burglars will favour properties that don’t have CCTV). Schools may use CCTV to deter and monitor vandalism and poor behaviour and even the quality of teaching. Care homes also use CCTV to monitor the health and wellbeing of residents (and there have been upsetting incidences of staff abusing patients caught on camera). Video-enabled baby monitors (or ‘NannyCams’) are increasingly used by parents to keep an eye on their offspring (or even pets, when they are out at work!).
Estimates vary enormously, but it is believed that the UK has the highest number of cameras per citizen – state-run and privately-owned – of any country in the world, including totalitarian and police states. Residents of large cities going about their day-to-day business may be caught on upwards of 70 different surveillance cameras each day!
The first applications were live only; there had to be a person monitoring the camera feeds at all times. With the advent of video recording equipment, footage could be saved for later retrieval. Multiplexing allowed multiple camera feeds to be recorded at once, and the technology shifted from analogue recordings on cassette tape, to digital recordings on tape, to digital recordings on computer hard drives and more recently, cloud-based storage. Many modern systems allow the camera feeds to be watched remotely via the internet.
Some systems have been criticised for poor security; for example broadcasting feeds over the internet with poor encryption, or easily-guessed passwords. This allows unauthorised access to what should be a private feed. How could you use this in your book? Could malign individuals use this to help them plan a crime or keep tracks on someone (for example a stalker or sexual voyeur), or could law enforcement exploit this to monitor a suspect?
Dispelling Myths
The ubiquity of surveillance can make one wonder exactly how a crime writer can go about setting a crime in a large city, without their perpetrator being caught on camera, identified and arrested before the end of the prologue – but fear not, there is no need to move your novel to a remote island or set your books no later than the end of The Second World War.
The quality isn’t always that good. We’ve all seen it; blurry, pixelated images or videos released by the police in the hope of identifying a suspect. How often have you looked at black and white images and found yourself just taking the police’s word for it that the indistinct shape is even a person, let alone somebody you may recognise? The haunting images of the toddler Jamie Bulger being led away to his death by two young boys in 1993 were full colour, but other than identifying the colour of their clothes, probable ages of the two suspects and the time that they snatched him, the evidential use of that footage was more in establishing the events that happened than directly identifying his kidnappers.
For video footage, older systems in particular used lower frame-rates to squeeze more hours onto the recording media, therefore the video is jerky and the suspect may only appear in one or two frames.
Obviously, the specialist officers that spend their working days staring at such video are more practised than you or I, but sometimes you wonder how useful releasing such footage might be. However, the human brain is a funny thing, and whilst a stranger might not see anything of any use in such images, somebody familiar with the person on the screen may see something they think they recognise. Sometimes that’s all that is needed; another name to throw into the mix. The police can then investigate that person and either eliminate from their inquiries or perhaps dig a bit deeper to find more compelling evidence.
Of course, modern cameras are light-years ahead of what was available even ten years ago. A couple of hundred quid can buy a high-resolution, full-colour system that can record easily-identifiable images, even in low-light. You can even buy smart doorbells that record footage of anyone ringing your bell, or can be triggered by anyone stepping within the camera’s range.
Could your book feature a suspect caught near an area by a neighbour’s CCTV? Although this is not evidence that they committed the crime, could it be used to prove or disprove an alibi, or show that they had the opportunity, as they were in the area at the time?
You can’t zoom in. Contrary to what Hollywood would have us believe, you can’t just ‘zoom in’ or magnify an image to gain more detail from previously-shot footage. Whilst specialist technicians may be able to ‘clean up’ images, removing static or adjusting the colour, ultimately, the laws of physics come into play. The recording can only display information from the photons of light energy that the camera picked up at the time.
Take a car licence plate – if it is blurry or too small to read on the original image, then no amount of enhancement will magically make it readable. Images that are borderline might benefit from interpolation, where complex computer algorithms can ‘guess’ what some of the missing pixels may look like, maybe by comparing several different frames from a video, and perhaps using other sources of information to confirm those guesses (eg comparing the shape of the reconstructed image to a database to work out what the digits are most likely to be), but the options are limited.
Could blurred footage collected at the beginning of a story be used by your detectives later in the book to strengthen the case against a suspect? Could you use the need to send a tantalisingly blurred photo off for specialist enhancement as a way of controlling the pace of your story?
Video that has been recorded over is permanently destroyed/can be retrieved at will
This subheading appears contradictory – and this is deliberate. Most video systems have a finite amount of storage. Typically, they are configured on a ‘rolling basis’. When the recording media is full, the system copies over the existing footage, replacing the oldest footage first. So even if a CCTV unit has been running for twelve months, there may only be the most recent month stored on the system. And as it continues recording, the older footage disappears, so that only the most recent month is on there.
Data Protection laws also dictate how long security footage can be kept for. For example, your local supermarket doubtless records customers throughout the store. Their data protection policy will determine how long they can retain that footage before they need to delete it. The exception of course is if they have reason to suspect that there is evidence of criminality etc on a particular piece of footage; then they are allowed to keep it until it has been used in court etc.
Whether this deleted/written-over material can be retrieved depends on the system used, how many times that tape, or that hard-disk sector has been over-written, the quality of the recording material etc. Forensic specialists might or might not be able to revive footage of sufficient quality to be any use.
As a writer, this ambiguity is great! You can decide whether or not your story needs the footage to be retrieved and then write accordingly.
‘Sorry, Sir, the footage has been recorded over too many times, we can’t bring it back’.
Or
‘We managed to retrieve some of the deleted footage, you can clearly see the suspect’s car.’
If you write it confidently, avoid naming specific systems or tripping yourself up with technical details, your readers will accept this. It helps if you foreshadow this when you hand it to your forensic specialists.
‘Robertson looked at the CCTV unit dubiously. “No Promises, Sir, this system does a really good job of erasing older footage.”‘
In this post I have only touched upon the basics. Next week’s post will delve into the subject in more detail. I will cover night vision and Automatic Number Plate Recognition. The concluding article will discuss some more recent innovations that you might find useful when writing your novel.
Until then, thank you for reading this far. Feel free to comment here, or on social media.
Best wishes,
Paul
