> The principles of the law makes it clear that it's far, far worse to have an innocent person in jail that a guilty person go free. Many legal principles revolve around this.
Yes, absolutely. But there are two issues in this context.
The first is that facial recognition isn't a conviction. Presumably if it identifies the wrong person then they'll have the opportunity to demonstrate who they are, e.g. by showing that the name on their ID is not the name of the suspect, before being convicted of the crime.
And the second is that ordinary application of that principle is incompatible with eliminating the disparity, because if you shift in favor of false negatives in general then it reduces the false positive rate for all races but the proportions stay the same. But if you shift it only for one race then you're only making the existing racial disparity in false negatives even worse, which is hardly fair to minority communities because it implies they'll have a higher proportion of criminals on the streets victimizing their communities.
That being said, in this context having a preference for false negatives over false positives in general probably is a good idea, and it does reduce the absolute (rather than proportional) racial disparity in false positives -- which is not nothing. But it's the proportional disparity that people are always complaining about.