Why forensic facial comparison can never be like the gold standard of forensic DNA analysis

There is a recent perception in forensic science that all methods of analysis should approach the ‘‘gold standard’’ of DNA analysis. This paper will examine the potential for such an expectation to be met in the nascent forensic science sub-discipline of facial comparison. Turning to first principles of biology and genetics, and moving through to application of scientific knowledge in the forensic context in facial comparison and DNA profiling, the paper will critically consider the actual and potential degree of commonality between the two. The significance of biological function, the genetic basis of individual variation, statistical comparison, historical and contemporary empirical studies, Darwinian selection and environmental influences will be systematically considered— where known. Particular attention will be paid to the work of Alphonse Bertillon, especially as applied to faces. The significance of techniques in ‘‘facial mapping’’ will also be considered. The paper will conclude that facial comparison can never approach the rigor of forensic DNA analysis and will consider the degree to which the expectation that all forensic sciences can meet the gold standard of forensic DNA analysis is naive.