DNA profiling and databasing technologies have become integral to criminal justice practices in many countries, and their reliability is now rarely challenged. However, a new set of forensic genetics technologies has emerged, one of which is forensic DNA phenotyping (FDP). FDP aims to infer a person’s visible traits from DNA, and to predict biogeographical ancestry, in order to provide intelligence for difficult investigations. Debates around FDP have been largely academic and legal, but in some countries they have become of public interest. Here, many scientists and practitioners tend to avoid publically articulating disagreement about the limitations of such technologies. This paper attends to a rare public disagreement about technoscientific practices in the wider forensic genetics community about a commercial forensic service called Snapshot™ which utilises FDP. Its analysis of scientists’ ethical reasoning about the development and use of this set of technologies contributes to understanding the political economy of forensic genetics, at the intersection of scientific ethics, forensic practice, and commercial resources that make visible and enable further scientific research in the field. More widely, this paper proposes that attending to public ethical debates such as this offers much-needed insight into the various intersecting stakes that co-constitute emerging technologies.