The spotlight is back on the Crown Prosecution Service as it has promised to review all 600 rape and sexual offences cases on its books in the light of the failure of cases involving the late and the very late disclosure of undermining social media content.

Why have these cases failed? What is it about digital disclosure and today’s use of social media that has made the task of fairly disclosing material so difficult? The answer may lie in that the police, prosecutors and defence lawyers are not sticking to basic principles. Digital disclosure may be a challenge but it need not be an impossible one.

Core duties

The basic principles are easy enough. Police investigators have a duty under the Criminal Procedure and Investigations Act 1996 to pursue all reasonable lines of enquiry including those that point away from the suspect and to retain material deemed to be ‘relevant’. Should the prosecution not use that material in its case, the ‘unused’ material need not be disclosed to the defence unless it could reasonably be considered capable of undermining the prosecution’s case or assisting that of the defendant. Routine examples of disclosed, unused material include the statement of an eyewitness with a materially different recollection from others or the previous convictions of a prosecution witness. But when it comes to dealing with the vast amount of material generated through social media, the system appears to have driven into a quagmire.

The social media quagmire

Social media, instant messaging and photo sharing may all be placed in the category of digitally stored material. In July 2011, the Attorney General published Supplementary Guidelines on Digitally Stored Material on how such material ought to be handled, now incorporated into the Attorney General’s Guidelines on Disclosure, 2013. The guidelines do not mention, once, social media or even smart phones. Yet, in the six-and-a-half years since their publication there has been an exponential increase in the use of such platforms and devices. Perhaps it is their omission from the guidelines that explains why they are seldom followed when detectives are investigating social media material.

In the year the Attorney General’s digital guidelines were published, Ofcom reported that a quarter of British adults owned a smartphone. By 2017, that figure had jumped to more than three quarters. The amount of data a smartphone can hold has shot up in the same period. Apple’s latest iPhone X can hold up to 256GB of data on the handset alone. Cloud connections allow even greater amount of data to be stored and accessed through a smartphone. Popular email platform, Yahoo, now offers 1 terabyte (1,024 GB) of free storage space.

The messaging platform, WhatsApp, barely existed in 2010. It now claims over a billion users worldwide. These messages cost nothing to send, in contrast to SMS messaging a decade ago. The relentless rise of text-based applications is in lockstep with the increase in smartphone take-up. It is now safe to assume that everyone arrested has, in his or her pocket, a device capable of accessing millions of messages and tens of thousands of photographs, with even more information such as websites viewed and physical locations visited.

But, despite the age of the Attorney General’s digital guidelines, they are far from obsolete. Technology designed to search a mass of unstructured and semi-structured data is capable of assisting the parties in a case sift through enormous quantities of social media. Indeed, had the guidelines been followed and the right techniques used, the quagmire could easily have been bypassed.

Digital disclosure strategies

In cases involving very large quantities of data, the investigator should put in place a strategy setting out how the data will be analysed or searched to identify categories of data. In common cases involving interaction on social media, the investigator will be on the look out for text messages between various relevant parties. There is no need, as a matter of common sense and as a matter of law, to read every single message. Cases that have come to grief seem to have done so because of a belief by detectives that every message needs to be read. As a consequence, the task either takes too long and results in late disclosure or it is seen as so daunting that it is kicked down the road, leading to delay and late disclosure. It is a well-established principle that the rights of complainants to privacy (guaranteed by Article 8, ECHR) means the prosecution should not simply offer up the full download of a complainant’s mobile phone. Disclosing everything and letting the defence bear the burden of investigating the material is no solution.

Any digital disclosure strategy focusing on social media will set the parameters according to the facts known. It is at this point the investigation will focus on particular devices, certain people, a date range and, crucially, keywords to be searched for. Once the data has been transferred into a format allowing appropriate searching, this task should be straightforward.

The strategy should be collaborative. The prosecution lawyers should inform the defence of the keywords to be searched for or actually searched for, and ask the defence to suggest their own. The guidelines specifically contemplate such a dialogue taking place.

The recent media attention has been on rape and sexual assault prosecutions, although the guidelines are applicable to all cases. In sexual cases, the complainant and the defendant are often known to each other and have communicated electronically before and after the alleged offence. In such instances the police will obtain the mobile phones of both parties and make a forensic image of them. Both forensic images now ought to be searched for the same keywords. The police will have theirs and the defence will wish to add to them.

Where keyword searches are done at present too often it is a basic, ‘ctrl+F’ search on Microsoft Excel or Word. Social media communication, however, will often fall through the gaps of a basic search. The way people communicate through instant messaging is much closer to spoken than written English, with abbreviations, slang terms and, of course, emojis frequently used. These difficulties can be solved through the use of more sophisticated searching techniques which use artificial intelligence, such as natural-language processing.

Recording the searches done need not be a burden, if done sensibly. A record ought to be kept of when searches were made and who did them. In a complex search, as above, the broad category of the searches might be sufficient. Each result might necessitate a further search. If so, this should be recorded. Finally, the actual message (or other data) brought up by a hit must be logged. If the smartphone contains data in a foreign language, keyword searches should be defined in English and then translated, with the translated words deployed in the word search.

The result would be an approach that doesn’t tie up valuable public resources sifting through vast quantities of data and ensures all participants can have confidence that the data has actually been searched for relevant material. As the Attorney General’s guidelines (2013) expressly state [at para 48]):

‘Where…investigations involve digital material, it will be virtually impossible for investigators (or prosecutors) to examine every item of such material individually and there should be no expectation that such material will be so examined. Having consulted with the prosecution as appropriate, disclosure officers should determine what their approach should be to the examination of the material.’

None of this is new. But, if recent case failures are anything to go by, this protocol is rarely heeded in practice. We still see digital evidence gathering and disclosure left as an afterthought, in many cases. We still see the assumption that once a smartphone comes into the possession of the police, a duty exists either to hand over all the data or to pledge review of a full download. Seldom, if ever, have defence solicitors been invited to suggest keyword searches, let alone actually provide them.

Keeping up our guard

With public confidence in so many institutions pretty low, the criminal justice system cannot afford to let its guard down. If basic principles are applied and applied scrupulously, the advent of social media and smartphones need not be the albatross they have recently become.

Contributor Richard Hearnden is a barrister at Furnival Chambers, London