DNA as ‘ready-made evidence’: An analysis of Portuguese judges’ views

The introduction of biological evidence in judicial settings raises particular modes of entanglement between professional cultures and perceptions of the probative value of evidence. When DNA evidence reaches court, it also challenges the perceived margins of critical assessment of the work and understandings of previous links in the chain of custody, like the criminal police, forensic experts and the public prosecution services. Given the apparent neutrality of judicial institutions, how do Portuguese judges perceive and value biological evidence? And how do judges see their articulation with other operators of the criminal justice system? An analysis of 14 interviews carried out with Portuguese judges reveals the challenges in the evaluation of biological evidence, which is characterised as a ‘safe haven’, grounded as it is on an indisputable scientific authority. The suggestion of the presence of a cultural rift emerges, which, taken with the work of other epistemic cultures, leads to biological evidence being seen as ‘ready-made evidence’ on its arrival in court, thus limiting the role of judges in its appraisal.