Acts of extreme or mass violence perpetrated by lone offenders have become increasingly common in liberal democracies over the past 20 years. Some describe these acts as politically motivated, while others attribute them to mental disorder or criminal intent. However, there is an increasingly common view that the distinction between political ideology, criminal intent and personal motivation is blurred, and that the violence carried out by these individuals is better understood using the broader concept of grievance-fuelled violence. This work employs a multifaceted analytical approach to develop a holistic model of the processes of grievance development.