The ICC relies mainly on testimonial evidence to determine the responsibility of the accused for international crimes. In particular cultural understandings have come to play a large role in the fact-finding process through testimonial evidence. The Katanga trial judgment specifically stressed that numerous sociocultural aspects in testimonial evidence were discussed further during the proceedings as a result of questions from judges themselves. In the absence of information as to which specific aspects required further questioning, this chapter examines the fact-finding role of judges during the proceedings. Through an exhaustive analysis of judges’ questions during the Katanga proceedings, the chapter explores which sociocultural aspects may require extra scrutiny during both the investigation and prosecution of crimes at the ICC, and how this may be implemented throughout the proceedings. It is argued that understanding the relationship between culture and testimonial evidence during proceedings is crucial for international criminal justice