We created an inventory of best practices, lessons-learned, and roles and responsibilities, to analyse how social media is being used by police and other public security planners, within and outside Europe.
Using data from academic literature, the review of blogs, books, existing best practice descriptions and expert knowledge, we identified 69 practice patterns that describe and structure the use of social media for public security (Figure 1). The patterns are structured in three groups, describing how (1) law enforcement agencies (LEAs), such as the police, (2) citizens and (3) criminals, are using social media and impact public security. With 49 patterns, the focus of this work is on group (1), the social media use of LEAs.

Each pattern has a unique name and describes a solution to a recurring problem or context. Following an image and a summary of the pattern, we provide links to online resources that detail the given practices. The patterns have been designed to be printed and shared as input for workshops and strategic discussions of practitioners and public security planners.
Patterns link to other patterns and thereby form groups. The main groups for LEAs are the use of social media for INTELLIGENCE, ENFORCING THE LAW, CRIMINAL INVESTIGATIONS and ENGAGEMENT & COMMUNICATION. Additionally, we describe a range of SOCIAL MEDIA FOUNDATION practices that allow organisations to prepare themselves and sustain the use of social media.
LEAs typically start their social media efforts by implementing the INFORMING CITIZENS pattern, which has become a quasi standard. LEAs widely acknowledge the benefits of using social media for ENFORCING THE LAW, especially in crisis situations. With regards to SOCIAL MEDIA MONITORING and CRIMINAL INVESTIGATIONS the scope and technological depths of adaptation varies. While already common practice in selected countries, such as the Netherlands and the United Kingdom, a more interactive COMMUNITY ENGAGEMENT, typically points to more experience in using social media, as it requires organizational change that empowers local officers to publicly post and interact digitally with citizens. Other practices such as ONLINE PATROL are still in its infancy and require LEAs to establish a visible presence in online spaces.
While some patterns are widely used and feature many examples, other practices have only been applied in selected contexts and are at an experimental stage. We therefore understand our work as a snapshot of current practices that will and should evolve.

The compilation shows the great potential of social media for public security. It should not be confused with a report on the state of current state of social adaptation. Indeed, our work indicates that adoption greatly varies and most LEAs have yet to define their role and responsibilities in digitised societies.