R v Richards and R v Bater-James: The Case Law Every Investigator Handling Digital Material Must Know

By Bob denaro (KPM) @ the BDG Training Team · June 2026

Two Court of Appeal authorities define how investigators must manage digital material: R v Richards & Others [2015] EWCA Crim 1941 and R v Bater-James & Anor [2020] EWCA Crim 790. Their principles apply to every CPIA bound investigation involving digital material, regardless of scale. The obligations do not diminish because a case is smaller.

R v Richards & Others [2015]: disclosure must be planned from day one

[2015] EWCA Crim 1941

The definitive authority on managing voluminous digital material in complex criminal prosecutions.A large-scale fraud investigation resulted in the seizure of numerous computers. At the time (2011), the largest tax investigation ever undertaken by HMRC, 8 defendants, the Indictment included conspiracy to cheat the public revenue, money laundering, and conspiracy to pervert the course of justice.

A professionally planned tax evasion scheme. A series of fake business entities purporting to make £270 million in losses to offset for tax purposes.Despite the prosecution case being served, the matter did not progress beyond primary disclosure for five years — the sheer volume of digital material (7 terabytes) was never properly managed.

The trial judge stayed the prosecution as an abuse of process. The prosecution appealed the terminating ruling. The case ultimately proceeded — and was successful for the prosecution, with 6 of the 8 defendants convicted.

The Court of Appeal's guidance from this case continues to govern practice across complex digital investigations.The Court of Appeal allowed the appeal and provided detailed guidance for the management of digital disclosure in large-scale cases.

The Court of Appeal used the case to issue definitive guidance on digital disclosure obligations under the CPIA. The message endures: disclosure is not an end-of-investigation task — it must be planned from day one.

Key principles

1.     Formulate a strategy. Initial disclosure requires the prosecution to formulate a strategy, canvass it with the court and defence, then use technology to carry out searching and sampling. An effective disclosure strategy is an essential part of an effective case strategy. Get a grip at the outset.

2.     The Impossible is Not Required. The prosecution is not required to do the impossible. Common sense must be applied — flexibility is critical

3.     Review proportionately. You do not need to examine everything — but you must record your approach. As a case progresses, searching and sampling may need to be re-done. That does not of itself render the original approach invalid.

4.     Engage early. "There is a defence duty to engage with the prosecution and thereby assist the Court in fulfilling its duty of furthering the overriding objective."

5.     Record Keeping . The prosecution is under a duty to properly log and record the strategy and analytical techniques used to search the data. The DMD must explain what the prosecution is doing — and importantly, what it will not be doing at each stage.

R v Bater-James & Anor [2020]: the leading modern authority

Bater-James builds directly on Richards and is also a leading case on digital disclosure. The Court set out a clear framework, from the moment material is identified through to unused material review.

The four Bater-James principles

1.     Reasonable lines of enquiry only. Digital material should only be reviewed in pursuit of a reasonable line of inquiry. There is no presumption that a complainant's or witness's device should be inspected, there must be a properly identifiable line of enquiry, speculative fishing expeditions are not permitted.

2.     Staged and proportionate approach. If review is necessary, investigators must decide how it is conducted. An incremental and staged approach minimises intrusion — seizure of the physical device is not always required.

3.     Keep the witness informed. Complainants and witnesses must be informed about the scope of digital review: what data is extracted, retention period, potential disclosure, and redaction of strictly private information.

4.     Consider the consequences of refusal. The court must consider the impact if a complainant refuses access or deletes material, balancing the defendant's right to a fair trial against the complainant's right to privacy.

Annex A: the definitive framework

Annex A of the Attorney General's Guidelines on Disclosure (updated February 2024) sets out the definitive framework for investigators and prosecutors handling digital material, from seizure through to trial. It is essential reading for any investigator handling digital evidence.

Training that covers this

Richards, Bater-James and Annex A are covered in depth in BDG's CPIA Disclosure Training, tailored for local authority and public sector investigators. Email info@bdgtrainingconsultancy.co.uk.

This article is adapted from the BDG Investigator Bulletin, Edition 3 (June 2026). Download the full edition free — and subscribe to receive each monthly edition by email.

This article is provided for professional development purposes and does not constitute legal advice.