Yes, real life is a bit different from reel. However, an UMbRA search should take seconds or only a few minutes, especially if you also have any other indicators that could help you look at the results you get and sift through them quickly — name, approximate age, ethnicity, race, general geographical region or any other descriptor.
The algorithm also works much faster than you could, sifting through a database of multiple millions. You couldn’t do that. Humans have a limited capacity when it comes to retaining memory of faces, about 2,000 typically, if that (most of us have had those moments when we think we’ve spotted someone familiar but just can’t remember that person’s name). Machine intelligence far outstrips human capacity on that front, both in terms of retention power, and processing power.