Visualizing uncertainty : anomalous images in science and law

Challenges to the reliability of scientific evidence are increasingly common. Where DNA is concerned, this distrust has been most often associated with problems in forensic laboratories such as inconsistent quality standards, cross-contamination, sample mix-ups and even the falsification of results. Yet, the recent emphasis on the scientific analysis of low quantity DNA samples - referred to, variably, as degraded, low copy number (LCN) or trace DNA - has reoriented theoretical and analytical attention to the 'visual' as the privileged source of knowledge to discriminate these otherwise undetectable 'non-conformities'. Paradoxically, the uncertainty rendered through the visual profile emerges as a result of the technological innovation purporting to improve results by increasing sensitivity and detection. This study traces uncertainty as it is exemplified through ambiguous visual constructs produced in the forensic laboratory, the translation into statistical probabilities, and the subsequent controversies such imagery has provoked in legal domains.