The definition of "match" is complicated, and not just for issues like partial fingerprints and blurring. The FBI says they had a "100 percent match" in the Mayfield case. The judge says this assessment was "fabricated and concocted by the FBI and DOJ".
"When police retrieve a print from a crime scene, they consult an FBI computer database containing millions of fingerprints and receive several possible matches, in order of the most likely possibilities. Dror found that experts were likely to pick “matches” near the top of the list even after he had scrambled their order, perhaps because of the subconscious tendency to overly trust computer technology.
“People would say to me fingerprints don’t lie,” Dror says. “And I would say yes, but it’s also true that fingerprints don’t speak. It’s the human examiner who makes the judgment, and humans are fallible.”"
The problem with these things is that the police are on the one hand of course doing their best to nail the actual criminals but on the other that when they get it wrong lives are ruined and there are zero repercussions. If you have an otherwise functioning legal system without plea bargaining and other 'efficiencies' then you at least stand a chance to fight the system. But here that is not the case and the combination of those two is extremely dangerous.
The Shirley McKie case was in Scotland, which doesn't have US-style plea bargaining. McKie accepted £750,000 in full settlement. There was a public inquiry https://en.wikipedia.org/wiki/Fingerprint_Inquiry .
The definition of "match" is complicated, and not just for issues like partial fingerprints and blurring. The FBI says they had a "100 percent match" in the Mayfield case. The judge says this assessment was "fabricated and concocted by the FBI and DOJ".
Or from https://www.science.org/content/article/forensic-experts-bia... published in 2022:
"When police retrieve a print from a crime scene, they consult an FBI computer database containing millions of fingerprints and receive several possible matches, in order of the most likely possibilities. Dror found that experts were likely to pick “matches” near the top of the list even after he had scrambled their order, perhaps because of the subconscious tendency to overly trust computer technology.
“People would say to me fingerprints don’t lie,” Dror says. “And I would say yes, but it’s also true that fingerprints don’t speak. It’s the human examiner who makes the judgment, and humans are fallible.”"