Acts of extreme violence perpetrated by lone offenders have become increasingly common in liberal democracies over the past 20 years. Some describe these acts as ideologically motivated, while others attribute them to mental disorder or criminal intent. This has led to the development of distinct areas of research and practice. However, despite the enduring tendency to silo the actions of these offences, there is an increasingly shared view that the distinction between political ideology, criminal intent and personal motivation is in fact blurred. There are an increasing number of instances where assigning an offender to a particular category has proven problematic, and this has led to an emerging consensus that the use of ideology as a sole marker for motivation may be flawed. This presentation argues that the motivation for some instances of extreme violence defined as either terrorism, mass murder, fixation, stalking, or familial and intimate partner homicide may be better understood through an application of the broader concept of grievance-fuelled violence.