You're right. Hopefully they will have rules like this. But knowing police, even if these rules did exist many departments would still go "Facial match? Good enough"

I think the appropriate procedure depends on the ratio of true/false positives/negatives. This is basically the same discussion that occurred with covid tests, because the mathematics behind are identical. Looking at the Positive/Negative Predictive Value should give you an idea how much you should trust each assessment.

Based on the articles we’ve seen recently, it seems that the false positives are the main problem here, so perhaps the PPV isn’t high enough. Ideally, you would combine two types of methods so that at the end of the day you’ll get to a very high PPV and NPV. However, I’m pretty sure humans have a very low NPV. Hopefully, the PPV is a lot higher, but racism clearly isn’t helping here. Augmenting that appalling mess with a flawed system is still a step forward IMO. Well, at least it would be if the system wasn’t used to oppress and discriminate people.