Establishing the pattern of crime is fundamental for the successful investigation of international crimes (genocide, war crimes, and crimes against humanity). A pattern of crime is the aggregate of multiple incidents that share common features related to the victims, the perpetrators, and the modus operandi. Pattern evidence and analysis have been used successfully, mainly in the investigation of large-scale killings, destruction, and displacement; the use for sexual violence charges has been remarkablymorelimited. There is a need to overcome this gap by setting proper methods of data collection and analysis. At the level of evidence collection, under-reporting should be addressed through victimization surveys or secondary analysis of data available from different sources. At the level of analysis, the available evidence needs to be subject to impartial examination beyond the pre-conceptions of the conflict parties and advocacy groups, in compliance with scientific standards for quantitative, qualitative, and GIS (Geographic Information Systems)methods. Reviewing the different investigative experiences and jurisprudence will help to set the right methodology and contribute most efficiently to putting an end to the impunity regarding sexual crimes.