The journey to crime is a well-researched phenomenon in environmental criminology. Various studies have measured the distance between criminals' homes and their crimes, while examining the influences of offender and offense factors. Other research has explored the nature and characteristics of criminal travel distributions, including changes in offending probability by distance. This last requires an understanding of the shape of the journey-to-crime function, particularly its key components of distance decay (offending probability decreases with distance) and the buffer zone (a lower probability area surrounding an offender's home). However, it is difficult to study the shape of these distributions because of the data requirements. This article offers an overview of the buffer zone, its definition and characteristics, and two proposed explanatory theories. We then outline four critical research considerations and the ecological fallacy problem. Finally, we propose a testing procedure for the presence of a buffer zone in a sample of individual-level crime trips. Using simulation analysis, we conclude 50 or more observations are needed to reliably determine the shape of an offender's travel distribution, a number much higher than found in previous studies. We provide two case studies of prolific predatory offenders that show strong evidence of the buffer zone.The journey to crime (JTC) is an integral component of many criminal acts. It is also one of the most studied offender behaviors in criminology; for almost 100 years, researchers have measured the distance between criminals' homes and their offenses, while examining the influences of crime type, offender age, sex, race, and other factors. An understanding of crime travel is important for both theoretical and practical reasons. Crime trips are of central interest in environmental criminology, particularly for crime pattern and routine activity theories. Travel possibilities influence offender decision-making, target choice, and spatial displacement (Rossmo & Summers, 2019, 2022. Crime scripts are informed by mobility, and findings from JTC research help focus criminal investigations (Beauregard et al., 2007; Rossmo, 2000). Such knowledge also guides crime prevention strategies and risk assessments.While early research was primarily interested in crime journeys at the macrolevel, more recently scholars have begun to explore microlevel questions. The development of powerful computers, police record management systems, and geographic information system (GIS) software greatly facilitated this avenue of research. One of the better studied microlevel phenomena is the nature and shape of the JTC function (e.g., Ackerman &