Evincing Offence: How Digital Forensics Turns Big Data into Evidence for Policing Sexual Abuse

The widespread availability and use of digital devices both enables criminal acts and helps to detect them. The production and circulation of indecent images of children has been one area of crime that has transformed in recent years because of developments in modern communication technologies. Through in depth ethnographic observations and qualitative interviews with four police forces in England, this article examines the resources and labor required to turn digital footprints into evidence for the possession of indecent images. In doing so, our aim is twofold. One, we detail the formal and informal processes whereby large sets of data become discrete pieces of judicial evidence. A notable feature of these administrative and technical processes is that while criminal justice agencies often strive for linear investigations, such aspirations fail to acknowledge the messy interrelation of expertise and roles that underpin the transformation of digital devices into evidence. As a second aim, we seek to identify similarities and differences in the practices whereby evidence is constructed between digital and other areas of forensics. In particular, this analysis raises questions around the descriptive and normative adequacies of prevalent theories of objectivity for digital forensics.