[pjc50]

The US has systematic incentives in place to create this kind of system: private prisons and elected local chief prosecutors. Both of those are incentives for false positives.

It also lacks police oversight; the UK has https://www.justiceinspectorates.gov.uk/hmicfrs/ and https://www.policeconduct.gov.uk/ , which while they are far from perfect are at least organizations with the capacity to put out a report saying "here's what went wrong and how it should be fixed".

In the US all police accountability is local, which means that the >51% of the voters who prefer being tough on crime (more false positives in the hope of more "true positives") get what they want.