This study-based on a national data set ( N = 1,447)-focuses on extrafamilial sexual assaults and their mobility. Spatial information about the offender's house, the victim's house, and the crime scene was combined in mobility crime triangles. The findings reveal that most of the assaults fall in the categories of total mobility (42.78%) and offender mobility (33.10%). Our results also show the validity of the distance decay function with over 50% of aggressions occurring within 3 km of the offender's house. The analysis did not reveal the existence of buffer zones, probably due to the acquaintance between some of the offenders and their victims. The evidence suggests that environmental risk factors are more significant than individual ones when it comes to explaining the variation among mobility patterns in sexual assaults. Offenders appear to adapt their mobility patterns and modus operandi according to the environmental constraints. Often, offenders choose their own or their victim's house as a safe environment for performed sexual assault.