Over the past 30 years, Sweden has witnessed a growth in criminal gangs and violent extremism. Gun violence and the use of hand grenades in criminal conflicts is also on the rise and have only recently gained wide political attention. As an example, among males aged 15 to 29 years the risk increase for victimization was five-folded in homicidal and non-homicidal gun violence during a 20 years observation period. In a comparative perspective the rate of gun homicide victimization among males 15 to 29 years was higher in Sweden compared to other Western European countries. Simultaneously Sweden is among the European countries with the highest number of foreign fighters per capita who have joined terror organizations such as Al-Qaeda and Daesh, second only to Belgium and Austria. Criminal gangs, gun violence and violent extremism are prevalent, partially overlapping phenomena that constitute social challenges. This presentation is based on three studies in which the development of serious social risk and crime-extremism nexus in Sweden are presented and policy and practical frameworks discussed.