Using tools of optics, representation, and measurement in conjunction with machine learning and artificial intelligence, investigative practices are used to test what we know to be the boundaries of investigative practices and their expansion. Examining the conditions under which knowledge and factual information are produced, Anna Engelhardt, Francesco Sebregondi, and Stefanos Levidis, in conversation with Zoé Samudzi, discuss the development of new practices of decentralised investigation, ones that are context-sensitive, locally anchored, and often without a preexisting space or fora to be heard or seen. Navigating different modes of witnessing, each practitioner questions the kinds of accountability and ethical responsibility in the constitution of images and the limitations of computational imaging and modelling in truth-making and telling.