The fourth dimension: Time between crimes and impact on behavioral change in violent serial crime

While the time dimension is part of the definition of serial crime, little attention has been given to understanding offending timelines and the impact of patterns of shorter or longer delays between crimes on the evolution of series on the ability to link crimes. Given the scarcity of research focusing on the timelines of serial offenders, the current study aimed to (1) determine whether series can be classified based on their timeline trajectories (e.g., progressively shorter intervals or progressively longer), and (2) determine whether these timeline trajectories correlate with trajectories of behavioral consistency and change across series. Data included 43 homicide series encompassing 216 crime scenes. Trajectories were determined based on whether intervals increased, decreased, or remained consistent across series, and whether timeline trajectories and behavioral trajectories align. Results revealed that distinct timeline trajectories can reliably distinguish between series. Results also suggested a complex interaction between time between crimes and how this relates to behavioral consistency and change trajectories, thus, suggesting that time is a useful, but potentially separate dimension in the linkage process.