From "Law and Order" to "CSI," not to mention real life, investigators have used fingerprints as the gold standard for linking criminals to a crime. But if a perpetrator leaves prints from different fingers in two different crime scenes, these scenes are very difficult to link, and the trace can go cold.
They have a specific result though, which is that fingerprints from different fingers of the same person tend to be recognizable as coming from the same person, just from their characteristics. Was that also known for a long time?