The present study seeks to explain individual differences in self-reported politically motivated violence and vandalism, and participation within an extreme right-wing group. While violent extremism is highly debated, few criminological studies explicitly test factors that can trigger violent extremism. The present study addresses this gap by integrating two different frameworks: a perceived injustice and group threat-initiated model and an impulsivity-initiated model. We also investigate several intervening mechanisms. We draw on a sample of 705 adolescents and young adults living in Flanders, Belgium to test the strength of direct and intermediary effects of perceived injustice, perceptions of out-group threat from Jewish populations, ethnocentrism, feelings of superiority, moral support for right-wing extremism, and exposure to racist peers on politically motivated violence and vandalism. Results of structural equation models (SEM) indicate various direct and intermediary effects between both perceived injustice and violent extremism, and between impulsivity and violent extremism. Our model reveals the complex and intricate antecedents of violent extremism. Importantly, we find that feelings of injustice and unfair treatment are a major source of extremist violence, as they easily trigger often debated causes such as high in-group identification and ethnocentrism. Implications of these findings for preventing violent extremism are discussed, given the centrality of perceptions of injustice and threat.