How the photo evidence is proven

Evidence is only worth as much as it can be trusted. Every photograph published here is handled so that its date, its content, and the fact that it has not been altered can all be checked independently. This page explains, in plain terms, the measures used and the recognised standards they follow.

In one line. Each image is timestamped from the camera's own data, given a unique digital fingerprint (a SHA-256 hash), recorded in an append-only log, and the untouched original is kept safely — so any tampering would be obvious, and an independent expert could reach the same result.

1. What is recorded for every photograph

Measure	What it is	What it proves
Capture timestamp	The date and time the photo was taken, read from the photo's own camera (EXIF) metadata — not typed in by hand.	When the scene looked like this.
Device details	The camera make and model recorded by the phone or camera in the same metadata.	What took the photograph, helping tie a set of images together.
SHA-256 fingerprint	A 64-character code calculated from the exact contents of the file. Change a single pixel and the code changes completely.	The image has not been altered since it was logged — the published file can be re-checked at any time.
Evidence log entry	An append-only record listing the filename, capture time, device, fingerprint, file size and the date it was entered.	A continuous audit trail — the record grows but past entries are never rewritten.
Preserved original	The untouched original file is stored securely. Only a copy is published, each with its own fingerprint.	There is always a master copy to fall back on and compare against.
Privacy redaction	Before a copy is published, any vehicle number plates and any people's faces visible in it are blurred. The full, unaltered original is never edited and is kept on file.	The evidence — the waste, the location and the timestamp — is preserved, while third parties are not identifiable.

On each street page, a published photo is shown with its capture timestamp and, where recorded, its SHA-256 fingerprint, so anyone can see the same details that are held in the log.

A note on privacy. The photographs published here focus on the waste on the ground. To protect the privacy of passers-by and vehicle owners who have nothing to do with the dumping, the published copies have any number plates and faces blurred. The fingerprint (SHA-256) shown for a photo is the fingerprint of the published, redacted copy, so it can still be checked at any time; the untouched original is held securely by the moderator and can be produced if formally required.

2. How a SHA-256 fingerprint proves an image

A SHA-256 hash is a standard cryptographic function used across banking, software and legal technology. You feed in a file; it returns a fixed 64-character code. The same file always produces the same code, but the smallest change — cropping, editing, re-saving, even altering one pixel — produces a completely different code. It is not practical to work backwards or to craft a different image that yields the same code.

So if the code recorded in the log when a photo was first received still matches the code of the photo shown on the site (and the original held on file), that is strong, checkable proof the image has not been tampered with. Anyone with the file can compute the code themselves and compare.

Try it yourself. On Windows you can check any file's fingerprint with the built-in command: certutil -hashfile "photo.jpg" SHA256. It will return the same code recorded in the log.

3. The standard this follows

Handling of the images follows the ACPO / NPCC Good Practice Guide for Digital Evidence (version 5, 2011) — the long-standing UK reference for handling digital evidence for a court. (ACPO, the Association of Chief Police Officers, was replaced by the National Police Chiefs' Council in 2015; the guide was never superseded and remains the working standard.) Its four principles are:

Principle 1	No action taken should change data that may later be relied upon in court.
Principle 2	Where someone must access original data, they must be competent to do so and able to explain the relevance and implications of their actions.
Principle 3	An audit trail or other record of all processes applied to the evidence should be created and preserved. An independent third party should be able to examine those processes and achieve the same result.
Principle 4	The person in charge has overall responsibility for ensuring the law and these principles are followed.

In practice for this project: originals are never edited (Principle 1); only the moderator handles originals and can explain the process (Principles 2 & 4); and the SHA-256 fingerprints and append-only log are the audit trail that lets an independent person reach the same result (Principle 3).

4. Why this matters in law

Photographs and their metadata can be used as evidence, but a court will weigh how reliable they are and whether they can be authenticated. Recording when an image was taken, showing it has not been altered, and keeping a clear chain from the original to what is published all go to that reliability — and are exactly what would be needed to support a resident's action under the enforcement routes described on the Your rights page (for example a Litter Abatement Order under section 91 of the Environmental Protection Act 1990).

Please note. This page explains the methods used to keep the evidence trustworthy. It is not legal advice, and whether any particular evidence is admissible or persuasive is ultimately for a court to decide. The full, unaltered originals and the complete log are held by the moderator and can be produced if formally required.

5. Persistent, uncollected waste — proven by timestamps

This is where the timestamps do their real work. Because every photograph carries its own capture date and time (and a SHA-256 fingerprint), the same accumulation can be shown in the same place across days and weeks. The Council states that a cleansing crew is allocated to The Mounts “for at least half a day, five days a week,” with an operative covering the area Monday to Friday (see Cleansing records). If that were being carried out, waste sitting in the same spot for weeks could not be repeatedly missed.

These independent, timestamped observations — not submitted through the Report It app — now have their own dedicated page, where the same spot is shown across multiple dates so you can see how long the material has remained in place.

See the persistent, uncollected waste evidence →

What this is — and is not. These are dated observations presented as fact. They do not allege that any individual has acted dishonestly; they let residents judge, from timestamped evidence, whether the described cleansing service is reaching these locations. The Council is welcome to respond (see the right of reply).

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