How Mass Public Shooters Use Social Media: Exploring Themes and Future Directions

This mixed-methods study examines social media use among public mass shooters in the United States as an extension of a comprehensive database of 170 mass shooters from 1966 to 2021. Here, we report findings from a systematic content analysis of public data and detailed timelines that were constructed for 44 mass shooters' social media habits and changes to those habits during the period of time leading up to their shooting. The paper also presents as a case study, a sentiment analysis, and term-linkage network for one perpetrator's total 3,000 tweets. Several themes were found in the data-there were shooters who changed their posting habits and in some cases, stopped using social media entirely in the lead up to their crime; shooters who used hate speech and were "radicalized" to violence online; shooters with a demonstrable interest in violence, who referenced past mass shooters in their own communications; shooters who exhibited signs of mental illness and suicidality; shooters who were already known to authorities; and shooters who like those described above, actively posted while shooting, presumably to boost their own celebrity status. The findings from this study provide insight into commonalities among mass shooters in terms of their social media usage, which could lead to new pathways for prevention and intervention.