So, when law enforcement says there is no match between fingerprints, keep in mind that there is no real standard for what constitutes a "match." Some experts will say 12 points is a match. Others will want up to 20 points. So, when Paul Holes says that none of the fingerprints match, he could be saying that there are not sufficient points that match for any expert to opine on whether the fingerprints match. That could be for a number of reasons: 1) each crime scene as prints from different hand(s) or fingers; 2) the partial prints are not clear enough for a multi-point match; or, 3) the partial fingerprints do not have enough print surface area for a match.
Holes also makes a very good point: even if a suspect’s fingerprints matched a letter or a cab, all that proves is that this person touched that surface at some point in his life. Fingerprints cannot be dated. So, for the Stine cab, all we would know is that a suspect touched that cab at some time… that could have been a week before the crime, an hour before the crime, or during the crime. With a letter, the suspect handled the letter at some point in time. That could be because the person wrote the letter… or the person could have simply touched the paper before the letter writer ever used that paper… paper is packaged by humans who handle the paper. A fingerprint on a letter, by itself, would not identify the killer.
Holes also makes a very good point: even if a suspect’s fingerprints matched a letter or a cab, all that proves is that this person touched that surface at some point in his life. Fingerprints cannot be dated. So, for the Stine cab, all we would know is that a suspect touched that cab at some time… that could have been a week before the crime, an hour before the crime, or during the crime. With a letter, the suspect handled the letter at some point in time. That could be because the person wrote the letter… or the person could have simply touched the paper before the letter writer ever used that paper… paper is packaged by humans who handle the paper. A fingerprint on a letter, by itself, would not identify the killer.
There would have to be a plausible way for the prints to have gotten there. If the guy didn’t work in a paper factory or work for the police, or some other possibility, then his prints on a Z letter are pretty damning.
Holes also makes a very good point: even if a suspect’s fingerprints matched a letter or a cab, all that proves is that this person touched that surface at some point in his life. Fingerprints cannot be dated. So, for the Stine cab, all we would know is that a suspect touched that cab at some time… that could have been a week before the crime, an hour before the crime, or during the crime. With a letter, the suspect handled the letter at some point in time. That could be because the person wrote the letter… or the person could have simply touched the paper before the letter writer ever used that paper… paper is packaged by humans who handle the paper. A fingerprint on a letter, by itself, would not identify the killer.
There would have to be a plausible way for the prints to have gotten there. If the guy didn’t work in a paper factory or work for the police, or some other possibility, then his prints on a Z letter are pretty damning.
Right. It would require some explanation. A good defense attorney may offer one. Without a concrete set of facts, it’s hard to say what the explanation would be for any individual. But, what does a fingerprint on a letter prove? it proves that you touched a letter. It does not prove that you wrote the letter. It does not prove that you committed the murders associated with the writer of the letter. Because reasonable doubt is such a high standard, if a fingerprint is all police have, it’s a weak case. Each element of a case has to be proven beyond a reasonable doubt. I don’t think a fingerprint on a letter with nothing more would lead to a murder conviction because I don’t think any prosecutor would bring the case on evidence so scant, especially such an old case.
In fact, in the Zodiac case, a fingerprint or DNA hit on the letters would not even support an indictment for murder. It would be probable cause to investigate the suspect, though. Remember, DNA broke BTK and EARONS because the DNA was acquired from semen samples recovered from the victims or the crime scene. It’s hard to explain that away. I don’t see Zodiac copping to murders based upon fingerprints or DNA left on a letter, that a) cannot definitively be tied to the killer (do we really know that the actual killer wrote any of the letters? Not really, but we have strong reasons to suspect he did. Suspicion isn’t proof beyond a reasonable doubt) b) can be explained away; and, c) is not a crime (writing a letter to the Chronicle posing as Zodiac would be in bad taste, but not necessarily a crime).
So, let’s say we develop a print off a letter and the print identifies John James Smith. So what? The police cannot prove that Mr. Smith committed any murders. They cannot put him at any crime scene. Now, if they search Smith’s home and find the LB hood and guns that match the crime scenes, case closed. If Smith is smart enough not to leave trophies or murder paraphernalia in his home and denies committing the murders, the police have little to work with based upon only a fingerprint on a letter or DNA from a stamp.
