David Keatley

Homicides are complex, dynamic crimes spanning periods of time. To fully understand homicides, investigators must understand not only what occurred but also when behaviours and events occurred. Understanding the sequence of homicides offers new insights into profiling and victimology. The current chapter outlines a new method for temporal analyses, Behaviour Sequence Analysis (BSA), which has already been applied to several homicide types (including murder, serial homicide, and terrorism). Drawing from the author's extensive work with police departments around the world as well as several recent publications from authors in the field, readers will gain an understanding of how to run their own BSA for research and investigative purposes. This is an exciting new area of research, and readers are encouraged to take the methods outlined in this chapter and begin applying them to their own case files and research projects. Additional methods based on the BSA approach are also outlined. Waypoint sequencing (Keatley and Clarke, 2021) provides a streamlined approach to sequence analysis, which was designed for live, real-time cases in which faster results are preferable. Behavioural fingerprinting is a new method for crime linkage, an important area of investigations and criminology, offering a new approach to linking crimes based on their sequential fingerprint.

Violence in serial homicide is a complex and dynamic part of an offender’s behavior. This chapter explores how aggressive and violent behavior is a part of serial homicide and the escalation of aggression to violence. The organized/disorganized dichotomy of serial killers and reactive and proactive aggression is used to help explain different types of aggression and how they may be exhibited during the commission of a crime. The proposed aggression–violence continuum conceptualizes aggression on a behavior continuum for offending behaviors and helps to visualize how violent an offender may be. The violence portion of the continuum is then further broken down into the tiers of serial violence that demonstrate an ascending level of violence and presents the escalating nature of serial homicide.