The issue of face recognition algorithms performing worse on dark faces is a major problem. But the other side of it is: would police be more hesitant to act on such fuzzy evidence if the top match appeared to be a middle-class Caucasian (i.e. someone who is more likely to take legal recourse)?
Yes.
> Does it return a list (sorted by confidence) of possible suspects,
Yes.
> ... or any other kind of feedback that would indicate even to a layperson how much uncertainty there is?
Yes it does. It also states in large print heading “THIS DOCUMENT IS NOT A POSITIVE IDENTIFICATION IT IS AN INVESTIGATIVE LEAD AND IS NOT PROBABLE CAUSE TO ARREST”.
You can see a picture of this in the ACLU article.
The police bungled this badly by setting up a fake photo lineup with the loss prevention clerk who submitted the report (who had only ever seen the same footage they had).
However, tools that are rife for misuse do not get a pass because they include a bold disclaimer. If the tool/process can not prevent misuse, the tool/process is broken and possibly dangerous.
That said, we have little data on how often the tool results in catching dangerous criminals versus how often it misidentifies innocent people. We have little data on if those innocent people tend to skew toward a particular demographic.
But I have a fair suspicion that dragnet techniques like this unfortunately can be both effective and also problematic.