RDR / Evidence and expert work / Overwriting, and why timing decides this job

Investigations & evidence · stopping the loop before it reaches your clip

Overwritten CCTV footage in Reading. It is recording over itself right now; the wall switch stops that.

Switch it off at the wall. Ten seconds, no cost, and nothing else you do will help as much. None of this involves a delete, and there is no bin to look in: the unit runs out of disk, returns to block one, writes new video across the old, and keeps doing it while the power is on. Quite how long that leaves you is not a question anyone can settle from a distance, and a firm quoting you a figure over the phone has not seen your system. Stopping the clock is the part you can do yourself, before you ring.

No files back, no fee — on most jobs Logged as an exhibit from the start The loop is recording over it now

Talk it through in confidence
0800 6890668

What is going on inside the disk.

How the cycle worksRecording runs the length of the disk, reaches the end, comes back to the front and puts new video where the old video was. Leave the unit powered and that cycle simply repeats. No file is deleted, nothing collects in a bin, and there is no undo to reach for.

Nobody can promise you a windowNot over the phone, and not from a model number. It comes out of the disk that was fitted, the number of cameras putting video onto it, resolution, frame rate, codec, and whether recording is continuous or movement-driven. Anyone giving you a figure without seeing the system is guessing.

Where the true answer liesOn the unit in front of you. Call up the playback calendar and write down the earliest date each camera still offers. That is your answer for today, and it moves forward with every hour the recorder stays powered. Note it before you touch anything else.

What overwriting really meansA block on a disk holds one value at a time. As soon as new video takes it, what was there has gone, with no earlier layer beneath waiting to be recovered. If the loop crossed only part of your period, fragments usually remain and we go after them. If it crossed all of it, nothing comes back, and any firm saying otherwise is selling you something.

Match the symptom to the fault.

Not here? Tell us what it is doing →

What you are seeing	What is likely wrong	What happens next
The recorder is still powered	Another hour of running costs it the oldest hour it has	Cut the mains at the wall
You have never been told how far back it goes	Capacity, camera count and the settings all shift it	Check the oldest date it holds
Some channels go back further than others	Movement-only recording on a quiet view fills very little	We check each channel on its own
The unit stopped working a fortnight back	A unit that stopped writing stopped overwriting too	Leave it off and send the drive
The date you want is no longer listed	Fragments usually survive past the index	The free check gives you a yes or a no
No claim and no enquiry has been opened yet	Paperwork moves far more slowly than the disk does	Get it copied today

Getting it to the lab: the lab takes parcels by tracked, insured post, and the return leg is at our expense. Unsure how to pack it? Ring before the box is sealed and an engineer will tell you what to send and what to leave out. The rest of the detail sits on the packing and postage page.

What we do, in order.

How other jobs ended →

Logged the day it lands, and the look costs nothing Free

A case number goes on your device the day it reaches us, and an engineer then finds the real fault — free, and before anything else happens. You are told plainly what will come back and what will not, with one fixed figure in writing beside it. Nothing chargeable starts until you have read that and said yes.

The look costs you nothingA fixed price, in writingStill nothing to pay

Nothing else gets written

Before anyone plays anything back on it, the recorder is stood down. Its disk is removed and cloned, sector for sector, through hardware incapable of writing back. With that clone made, your position stops changing: whatever the loop had not reached is inside the image and safe from anything done afterwards.

Power cut firstCopied through a write blocker

Which dates actually came through

That image is then interrogated for what it truly holds — earliest recording, latest recording, and every gap between the two. Where the loop took part of your period, that reading tells you which half-hours are there and which are not, and it comes to you as a written list before anything else is attempted. The reading itself costs nothing. The work is £400 + VAT, and on most jobs there is no fee if nothing comes back.

First and last dates listedEach gap named

Copied out, hashed and signed over

Whatever comes off legible goes onto new media as an exhibit — native recorder files, a copy that will play on any computer, MD5 and SHA-256 against each, plus a dated log naming every person who has had custody of it. Adjusters and officers investigating a claim recognise that package and expect it. There is a second gain: from that day the footage exists somewhere the recorder cannot reach, so the box can go back on the wall and the loop stops having a say in anything.

Hashed, logged and datedKept off the recorder

The list first, then the bill, then the files

You see the file list first, then decide. Nothing is invoiced until you have said yes, and on most jobs there is no fee at all if the data does not come back. What we pull off goes onto media bought in for your job, and the postage home is ours. The case stays open on the bench until you tell us the files open on your own machine.

Nothing billed until you say yesNew media, bought for the jobPostage home is on us

What we keep finding on recorders

Paperwork moves slower than hardware — claims and enquiries run into weeks. Have the footage copied, and settle the question of the invoice afterwards.
A broken unit is often the fortunate one — if it quit a fortnight ago it also stopped overwriting a fortnight ago, so what it holds is what it held then.
Cameras do not use the disk equally — a lens on the street door and one in a back stockroom fill space at wildly different rates, and where recording is movement-driven the quiet camera will hold much older material.
Check whether there is a second disk — bigger recorders hold two or more, and one of them may be an archive, or carry a retired set of channels reaching back past anything on the live disk.

One thing stops it, and only one: cutting the supply. No setting does it, no menu item does it, and no message left with the installer does it — the wall switch does. The system has to be yours, or one you have the right to have examined. From then on it moves at your speed. If a site truly cannot go dark, get the hours you need exported to a USB stick in the recorder's native format rather than a conversion, and speak to us before anyone else goes near the drive. Leaving it powered and hoping for the best is the option that fails: each hour it keeps running spends an hour you still had.

How one of these actually went.

PL · RDG-2026-2025ON FILE ✓

A Woodley trade unit, off at the wall by nine

The place had been entered overnight. Finding the shutter up, the manager went straight to the socket, took the recorder off supply before unlocking anything else, and then rang. By Tuesday it was here, and it was imaged before anybody had played a single clip. The full night came through, every clip carrying its camera and its timestamp, and the adjuster had a copy before the week was out. The surprise was how little the disk had been holding.

The clipscame off wholeHashedclip

What helps, and what makes it worse.

First things to do

1. Photograph the live view, with the clock in frame
2. Pull the recorder's supply out at the wall
3. Ring us before anyone opens the case
4. Tell your insurer in writing that it has been secured

What makes it worse

Leaving it switched on
Holding off until someone asks
Raising it with the installer and then waiting
Plugging the drive into an office PC

What people ask before they send it.

How far back will my recorder still reach?

Nobody can answer that from here, and a model number will not settle it either. The window falls out of five variables — disk capacity, camera count, resolution, frame rate, and whether the box records around the clock or only on motion. The recorder itself already knows: open its playback calendar, and the oldest date it will still show you is the honest answer. That answer shrinks every day.

Once something has been recorded over, is any of it left?

No. New video landing in a block ends the older recording that was there, and no program or bench reverses it. Partial cases are a different matter: where the loop covered only part of the period you want, fragments frequently remain beyond the index and are worth carving back. A free check tells you which of the two you have.

Do I cut the power to it?

Yes, if the premises can go a day or two without cover. Taking the mains away is the only reliable way to stop the loop, and it costs nothing. If the cameras have to stay live, export the hours you want to a USB stick first, save it in the recorder's own format rather than a converted one, and ring us before anybody opens the unit.

My insurer has not asked for it yet. Does that matter?

Secure it anyway. Claims and enquiries take weeks; the recorder moves at whatever speed its settings dictate, and that is usually the faster of the two. Written requests arrive naming dates the disk has already been round again. Having a copy taken today is cheap, and it closes the question either way.

If this sounds like yours, start here.

Clips for insurers and police → SD, CF and CFexpress cards → USB flash sticks and pens → Casework for court and claims →

Stop the loop before it reaches your clip.

The recorder is still writing, and each time it comes round it takes more of what you need. Pull its power now, then get it to us. The first look costs nothing, a fixed figure follows in writing, and nothing you tell us goes anywhere else.

0800 6890668

Get it quoted Posting it to Oxford

Drives, cards and whole machines

Start from the fault

Evidence, footage and reports

What it costs, and what happens