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ADR / Evidence, claims and footage / Overwriting, and why the timing rules it

Investigations & evidence · getting the loop halted short of your clip

Overwritten CCTV footage, London. It is overwriting itself as you read this. A switch on the wall ends that.

Disconnect at the wall. Ten seconds. No charge. And today this takes precedence over anything else you are likely to do. There was never a deletion made here and there is no bin holding your clip either; when the disk fills up, the recorder returns to block one, fresh video lands on top of what's already been recorded, and it continues around for as long as power remains on. Nobody watching from afar can tell you how much time is left: a number called down the phone line with regard to the remaining time is simply a number given with no view of the entire system. However, stopping the clock is something you can do, and you can do it before you make that call.

Only pay if we recover your data, on most jobs Handled as an exhibit from the moment it arrives Each hour the loop covers more of what is left

Talk it over with an engineer, in confidence
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What the recorder does to that disk.

What that loop is doingOnce recording begins, it travels down the disk and hits the end of it. At that point, it moves back up to the beginning of the disk and lays down new video footage over the old. If you leave the power connected to the unit, this process will repeat indefinitely. There is no deletion mechanism, and old recordings do not build up anywhere you could go and retrieve them from, so there is also no "undo" available.
No one can quote your windowThis information is not provided via a phone call, nor can it be obtained from examining the model number. Instead, it depends on the type of disk being utilised, how many cameras are currently recording to the disk, the camera resolution and frame rate, the codec used to compress the recordings, and whether the unit is always recording continuously or records only when motion occurs. Without having access to the unit and its configuration, any estimate of how much time is still available would be purely speculative.
Where the answer really isOn the unit itself. Each camera is assigned an entry on the playback calendar listing its oldest date. Note down each camera's oldest date on the calendar. The oldest date listed represents your current state, and it changes for every hour that the unit operates while powered on. This should be done before doing anything else with the unit.
What overwriting actually meansA single block on a disk only holds one value at a time. As soon as that block is occupied by new video, what previously occupied that block ceases to exist and there is no lower layer of earlier video waiting to be restored. In those cases where the loop has entered into only part of your time span, some segments of video often survive even though they are no longer listed in the index. We seek out these remnants. Wherever it has traversed your entire time span, however, all evidence disappears regardless of what a company claims.

What the symptom usually means.

Not listed? Tell us what it does →
What is going onThe usual reason for itWhere that leaves you
The recorder is still runningEvery hour of operation displaces the oldest hour on the diskTake it off supply now
You were never informed of how far back it retains evidenceIts capacity, number of channels and configuration all impact how far back it keeps videoRead the earliest date
Different cameras go back for varying lengths of timeA quiet view recording only during periods of movement uses nearly none of the storageEvery channel is read separately
The unit stopped working approximately two weeks agoWhen it ceased recording, it also ceased overwritingLeave the unit off. Obtain a quote first. Then post us the disk or deliver it to our Guildford intake laboratory, Monday to Friday, 9am to 5:30pm (no appointment needed)
The date associated with your recording has been removed from the calendarVideo may persist beyond the index that listed itThe free check gives yes/no responses
No claim has been filed yet, nor any enquiry initiatedThe processing speed of disks far exceeds that of paper-based processesCopy it today, not later
How it reaches us: get a straight quote first (via phone or form), then send it via tracked, insured post or drop it off at our Guildford intake lab, Monday to Friday, 9am to 5:30pm (no appointment needed); our Guildford lab takes it in, and the cost of sending it back to you is on us. Unsure what to put with it when sending it to us? Give us a ring before sealing your box and we'll put you through to an engineer who can tell you what you need to include and what needs to stay behind. All of this information is also outlined on our guide to packing and posting.

The sequence we follow.

Other jobs on the log →
01

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

As soon as your parcel arrives here, an engineer assigns a case number that same day, prior to determining what has really failed, which is the first thing done and costs you nothing. In addition to a note of what can and cannot be recovered from your drive, you will receive at the same time the fixed, written price for restoring what can be recovered. You can accept this quote, or decline it, which will result in no further obligation on your part and nothing owed to us.

Nothing to pay for lookingA single figure, put in writingNothing owed at this stage
02

No further writing at all

No playback occurs on the recorder; it is stood down first, and its internal disk is then removed. A sector-by-sector duplicate of the contents is generated using hardware unable to write anything. Once that duplicate has been created, your position cannot get any worse: whatever portion the loop had not reached is now contained in the duplicate image, out of the reach of anything that happens next.

Off the mains first of allCloned on hardware that cannot write
03

What the dates actually say

Next is determining what actual content resides on that duplicate image: earliest to latest recording(s), as well as gaps between those recordings. In instances where the loop extends into your time period, every 30 minutes is designated as present or absent on a written list, and you receive that list prior to proceeding with any other actions. The cost for creating that list is zero. Work leading to recovery of your data subsequently incurs a cost of £400 + VAT, and on most jobs you only pay if we recover your data.

First and last dates written outEach gap listed
04

Exported, hashed, handed over

All legible evidence is duplicated onto fresh media for purposes of establishing exhibits: the files created by the recorder, a playable copy that any machine will play, MD5 and SHA-256 hash values calculated for each file, and a dated log detailing custody of the materials. That specific package contains what investigators and adjusters typically require for their examinations. Additionally, duplicating your video provides an added advantage: with that copy beyond the reach of the original recorder, the recorder can be put back to work, and you effectively eliminate the need to consider timing restrictions imposed by its loop.

Hashes, an index and a dateHeld where the recorder cannot go
05

You see the file list before you pay

You will see what has been recovered as a list first, after which a bill exists. Accepting the list means that a bill will be issued. Rejecting the list means that a bill will not be issued, and in most cases you only pay if we recover your data. The recovered data travels from here back to you via new media purchased specifically for your project, with the cost of postage paid by us. Your case is not resolved (i.e., "closed") until you personally view the files on a computer of your own.

No charge until you accept the figureFresh media, supplied with the jobThe post home is ours

What the bench has learned

  • Hardware moves faster than paperwork: a claim or enquiry can take weeks of paper-based documentation. Duplicate your video footage now and settle the invoice later.
  • A unit that has stopped is often the lucky one: if a recorder halted activity fourteen days ago, it simultaneously halted recording activity, thereby preserving existing content as of that date.
  • The cameras are not equal on disk: views such as those depicting entrances/exits to buildings versus interior views of stockrooms consume space at vastly different rates. Moreover, when recording is performed only in response to motion, quieter views will contain significantly older content than busier views.
  • Look for a second disk: larger recorders commonly include multiple disks (two or more). One may represent archival content; alternatively, one may contain a set of retired camera channels going back further than anything live.

One thing halts it, and one only: turning off the supply. This is not a setting, nor a menu option, nor a message left with the installer: it is the switch on the wall. It has to be your own system, or one that you are lawfully permitted to inspect. After that, you set your own pace. If a place cannot truly go dark, put the hours you want onto a USB stick using whatever format is native to the recorder (do not convert it first) and call us before anybody handles the drive. The only approach that fails is leaving it powered up and hoping. Every hour of operation takes an hour away.

One job, followed all the way through.

LDN · ADR-2026-3425JOB LOGGED ✓

An Ealing unit, off the mains by nine

A break-in during the night. Upon arrival, the manager noticed that the exterior side door was open. He immediately turned off the power supply to the recorder (before he touched anything else), and then called. It reached us on Tuesday, and an image of it was created before anyone played any clips. Everything recorded that night was present, with camera and time stamp for every single clip, and the adjuster had a copy within a week. The surprise was how little data existed on the hard disk.

The footage came back entireHash-verified copy handed over

What helps, and what harms.

Do this much first

  • 1. Take a photo of the active screen display, including the clock
  • 2. Disconnect the recorder from the wall socket
  • 3. Call us before allowing anyone to open the unit
  • 4. Write to your insurance company advising them that the unit has been preserved

What sets us back

  • Leaving it plugged in
  • Holding off until somebody asks
  • Calling your installer and then waiting
  • Placing the disk into an office computer

The questions that come up first.

How far back will my recorder go?

From here, no one can tell. Neither can the model number decide it. Five parameters define the window between them: storage capacity of the disk, how many cameras feed it, the resolution those cameras use, how many frames per second, and whether it records continuously or only upon detecting motion. The recorder knows. Each camera's oldest date of recording is stamped on its calendar of playback activity, which is today's honest figure. And that will be a day worse tomorrow.

Once the loop has written over a clip, is any of it left?

No. New video added to a block obliterates whatever was previously stored in that block, and neither software nor a bench can restore it. Clips that were once listed but now are not are a different matter: the original video is still located below (unindexed), and often it can be recovered through a search by pattern. Knowing which is which is part of our free examination.

Should I cut its power?

Yes, provided that your business can survive without being covered for a day or two. There is nothing that breaks this cycle reliably except turning off the power source itself (free). If your cameras have to remain operational, pull out your desired number of hours onto a USB stick prior to doing anything else (in the native format used by the recorder, not converted), then call us before the box gets opened.

My insurer has not asked. Does it matter?

Secure it anyway. Weeks pass with claims and enquiries, while the recorder moves at whatever pace its settings set, and that is nearly always the quicker of the two. Requests for information finally come in later, in writing, naming dates that have already gone around the loop again since. An inexpensive duplicate created today will settle this issue either way.

Begin here if yours is doing the same thing.

Copies the police and insurers take → A card that reads empty → Pen drives and USB sticks → Work that reaches court →

Off the mains first, because that is what protects the evidence.

Regardless of what contains the evidence, turn off electrical power to it before doing anything else: a recorder still operating overwrites its oldest evidence every hour. Once power is removed, secure a price quotation (either by phone or through submitting a form), then post us just the disk or drive (do not include the recorder or computer), or drop it off at our Guildford intake lab, Monday to Friday, 9am to 5:30pm (no appointment needed). Evaluation costs nothing; work on recorders costs £400 + VAT and forensic analysis starts at £800 + VAT, both prices agreed to in writing beforehand. What sits on that disk stays here.

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