This research addresses the investigative strategies that police officers from traditional police departments pursue when dealing with social media in their investigations. There are a variety of ways in which social media can feature within a case. This study focused only on one of these - the social media material generated by the actors (victims, witnesses and suspects) within an investigation. It identifies the decisions that officers make when presented with social media within an investigation and what drives officers to make those decisions. It utilises the most up to date guidelines for good practice in relation to digital evidence centrally available to officers in England (ACPO,2012) in order to provide a benchmark against which to compare officers’ decisions and rationale. Due to difficulty in identifying established theory on investigator decision-making around social media encountered in investigations, grounded theory was adopted to analyse the primary data collected. This methodology is well-suited to building theory in a relatively unexplored field (Glaser, 1978; Schreiber, 2001; Goulding, 2002). Two police forces provided data for the research these being Thames Valley Police and Avon and Somerset Constabulary with two different data collection methods being used. The first was the collection and examination of crime reports and the second comprised of semi-structured interviews with investigators. Inlaying out the decision- making process that officer’s use, the research highlights where the opportunities lie for best practice and how to influence the behaviour of investigators in the future. The research identified social media as a new problem for investigators with unique facets to it. However, it found that investigators were using heuristics to inform their decision-making process. In so doing they were applying strategies to social media that are were not adequate to deal with it when considering their objectives.