Following the 1999 Columbine High School shooting, it was hypothesized that offenders used knowledge gained from news media reports about previous events to plan mass shootings. Although researchers have studied active shooter events, little research has been conducted on the factors that influence an active shooter's decision and ability to carry out such events. The purpose of this study was to evaluate the relationship between the rate of news media reporting about an active shooter event and the casualty rate of the ensuing event in the United States. The bracketed time of this assessment was between April 20, 1999, and June 15, 2016. The age and regional location of the subsequent shooters were examined as moderating variables. Social learning and social cognitive theories constituted the theoretical framework. Data were gathered from existing mass shooting and active shooter studies, Google News, and the ProQuest Central database. A Spearman's correlation analysis revealed no significant relationship between the rate of news media reporting about an active shooter event and the casualty rate of the ensuing event. The age and regional location of subsequent shooters were not moderating variables. However, a Spearman's correlation analyses did reveal a significant relationship between the casualty rate of an active shooter event and the amount of news media coverage the event received prior to the ensuing event. The study finding clarified the need for active shooter reporting guidelines, similar to existing suicide reporting guidelines. The implementation of such guidelines could reduce the regularity and severity of active shooter events, thereby improving public safety in the United States by reducing the regularity and severity of active shooter events.

Förekomsten av psykisk ohälsa bland ensamagerande våldsverkare i Sverige studerades genom en tematisk analys på textdokument. Trettiofem av 70 ensamagerande våldsverkare valdes ut genom ett systematiskt slumpmässigt urval. Textdokumenten innehåller sekretessbelagd information ifrån Polismyndighetens system. Av de undersökta ensamagerande våldsverkarna hade 43 % en psykiatrisk diagnos och tecken på psykisk ohälsa fanns hos 34 %. Resultatet går i linje med internationell forskning som visar att ungefär 40 % av ensamagerande våldsverkare innehar en psykiatrisk diagnos. Sammanfattningsvis i aktuell studie uppvisade 77 % av de ensamagerande våldsverkarna tecken på psykisk ohälsa vilket kan indikera att antalet med psykiatriska diagnoser i studien kan ha underskattats. Således visade studien att psykisk ohälsa är en viktig riskfaktor för våld och Polismyndigheten behöver samverka med andra samhällsaktörer för att kunna förebygga, förhindra och upptäcka brottslighet från ensamagerande våldsverkare. / The frequency of mental illness among lone actors in Sweden were studied through a thematic analysis on textual documents. Thirty-five of 70 lone actors were chosen with a systematic randomized method. The textual documents contain closed source data from The Swedish Police Authority. Of the studied lone actors 43 % had a mental disorder and signs of mental illness were observed in 34 %. The findings are consistent with previous international research that shows that approximately 40 % of lone actors have a mental disorder. In summary current study outlines that 77 % of lone actors in Sweden show signs of mental illness which can indicate that the quantity of mental disorders could have been underestimated. Finally mental illness appears to be an important risk factor for violence and The Swedish Police Authority needs to cooperate with other social actors to be able to prevent and discover violent crimes from future lone actors.