Over the last two decades, the analysis of DNA traces found at a crime scene have expanded the already established forensic DNA analysis for identification to include new techniques intended to predict a criminal suspect’s externally visible characteristics, such as eye, hair and skin colour (‘forensic DNA phenotyping’), or his or her ethnic, continental or regional origin (‘biogeographical ancestry’). In this paper, we conduct a dispositive analysis to investigate how extended DNA analysis in forensics catalyses inherent processes of racialization at three different levels: 1) in the categorizations that are integral to this technology, 2) in the images of the ‘dangerous other’ combined with inflated expectations regarding these technologies’ effectiveness that have framed discourses regarding the legalization of this technology, and 3) in the biases and stereotypes which often guide investigative practices using these technologies. We demonstrate that this is an example par excellence of how the interaction between different practice dimensions can exacerbate unintended discriminating, racialising and racist effects.