The growing philosophical literature on algorithmic fairness has examined statistical criteria such as equalized odds and calibration, causal and counterfactual approaches, and the role of structural and compounding injustices. Yet an important dimension has been overlooked: whether the evidential value of an algorithmic output itself depends on structural injustice. We contrast a predictive policing algorithm, which relies on historical crime data, with a camera-based system that records ongoing offenses, where both are designed to guide police deployment. In evaluating the moral acceptability of acting on a piece of evidence, we must ask not only whether the evidence is probative in the actual world, but also whether it would remain probative in nearby worlds without the relevant injustices. The predictive policing algorithm fails this test, but the camera-based system passes it. When evidence fails the test, it is morally problematic to use it punitively, more so than evidence that passes the test.

Unmanned surface vessels (USVs), which can patrol Singapore waters autonomously, have been on trial since late last year said the Singapore Police Coast Guard (PCG). Two of the USVs - one measuring 9m long and the other 16m - were showcased to the media yesterday, in the open water off Marina Bay. Leveraging on technology, USVs are part of Singapore's "multi-layered" defence, which also includes sophisticated land-based CCTV cameras and sensors, to protect its maritime borders. Said Superintendent Lin Zhenqiang, head of operations and security at the Police Coast Guard: "These USVs are able to conduct autonomous patrols. And this will help us project police presence."