zlacker

>>vermon+(OP)
This story is really alarming because as described, the police ran a face recognition tool based on a frame of grainy security footage and got a positive hit. Does this tool give any indication of a confidence value? Does it return a list (sorted by confidence) of possible suspects, or any other kind of feedback that would indicate even to a layperson how much uncertainty there is?

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)?

>>danso+02
I think the NYT article has a little more detail: https://www.nytimes.com/2020/06/24/technology/facial-recogni...

Essentially, an employee of the facial recognition provider forwarded an "investigative lead" for the match they generated (which does have a score associated with it on the provider's side, but it's not clear if the score is clearly communicated to detectives as well), and the detectives then put the photo of this man into a "6 pack" photo line-up, from which a store employee then identified that man as being the suspect.

Everyone involved will probably point fingers at each other, because the provider for example put large heading on their communication that, "this is not probable cause for an arrest, this is only an investigative lead, etc.", while the detectives will say well we got a hit from a line-up, blame the witness, and the witness would probably say well the detectives showed me a line-up and he seemed like the right guy (or maybe as is often the case with line-ups, the detectives can exert a huge amount of bias/influence over witnesses).

EDIT: Just to be clear, none of this is to say that the process worked well or that I condone this. I think the data, the technology, the processes, and the level of understanding on the side of the police are all insufficient, and I do not support how this played out, but I think it is easy enough to provide at least some pseudo-justification at each step along the way.

>>strgcm+w7
That's interesting. In many ways, it's similar to the "traditional" process I went through when reporting a robbery to the NYPD 5+ years ago: they had software where they could search for mugshots of all previously convicted felons living in a x-mile radius of the crime scene, filtered by the physical characteristics I described. Whether the actual suspect's face was found by the software, it was ultimately too slow and clunky to paginate through hundreds of results.

Presumably, the facial recognition software would provide an additional filter/sort. But at least in my situation, I could actually see how big the total pool of potential matches and thus have a sense of uncertainty about false positives, even if I were completely ignorant about the impact of false negatives (i.e. what if my suspect didn't live within x-miles of the scene, or wasn't a known/convicted felon?)

So the caution re: face recognition software is how it may non-transparently add confidence to this already very imperfect filtering process.

(in my case, the suspect was eventually found because he had committed a number of robberies, including being clearly caught on camera, and in an area/pattern that was easy to narrow down where he operated)