What Do Fingerprints Prove?

By now, you may be aware of my healthy skepticism when it comes to “scientific” evidence. Even top physicists these days claim that matter may not actually exist until we consciously observe it (cool stuff, but a Schrödinger’s Cat discussion is a topic for another day). So, when a lab analyst tells a jury that a defendant’s fingerprints “match” the prints found at a crime scene, we know that the analyst isn’t really saying that these fingerprints are from the same person–but rather–that the two sets of prints have a few unique characteristics that match. Retina scans, by comparison, can be far more accurate because our retinas have over 200 unique identifying characteristics (not so many unique characteristics to match up with fingerprints).

When defending a case involving fingerprints, what happens when the criminal defense attorney decides not to challenge the accuracy of the fingerprint analysis? Now what? Here’s a real life example of just such an instance.

In Cordero-Artigas v. State, the defendant was convicted of the manufacture of a controlled substance and possession of drug paraphernalia. 75 So.3d 838 (Fla. 2nd DCA 2011). Basically, he was convicted of owning a “grow house” for marijuana. It was Cordero’s fingerprints that got him in convicted. The Sarasota Sheriff’s Office had been watching a home for two months, suspecting it was a marijuana grow house. During these two months, only four people went onto the home’s property, Cordero was one of them (though he was never actually seen entering the home, just the garage). Eventually, the police obtained a warrant to search the home, and as expected, marijuana plants were growing inside. Four people were charged.

Nearby the marijuana plants, the police located two sheets of paper taped to the wall which contained instructions for fertilizing marijuana. Two fingerprints were found on these sheets, and Cordero’s prints were found on the back of one sheet and the front of the other instruction sheet. Over ninety prints were found in the grow house, and only these two prints matched Cordero’s prints.

Cordero testified at his own trial, explaining that the two fingerprints were there because he helped a co-defendant bring two air conditioners to the house, and Cordero noticed some papers on top of the air conditioners–but he didn’t bother to read them (he thought they might be warranty documents). At the time of this delivery, Cordero never witnessed marijuana in the house (of course, how could he, they didn’t have the a/c units there to cool down all the grow lamps…duh.). The jury convicted Cordero of manufacture of a controlled substance (marijuana) and possession of drug paraphernalia based upon the fingerprint evidence introduced by the state. On appeal, the court addressed the nature of these fingerprints, and found that “circumstantial evidence, including presence at the crime scene and fingerprints, is an ‘incriminating circumstance which the jury may consider as tending to show guilt if evidence thereof is allowed to go to the jury unexplained or unrebutted by evidence of exculpatory facts and circumstances.” Id at 839, internal cites omitted.

You see where this analysis is going? (hint, it’s not going good for the state) Circumstantial evidence is fine–until a Defendant is able to present exculpatory facts to rebut said evidence. That’s exactly what Cordero did, he told the jury why his fingerprints were innocently found where they were found. Once that happened, it then became the state’s burden to present evidence that would overcome Cordero’s explanation. The state did not, and Cordero’s conviction was overturned.

The court restated the long standing rule that “circumstantial evidence is insufficient to convict if the State’s evidence does not conflict with the defendant’s reasonable theory of events.” Id. At 842. “Mr. Cordero’s reasonable explanation that the papers were on top of the air conditioner box and that he slipped them into the box without reading them explains the presence of his fingerprints without knowledge of the crime. The State introduced no conflicting evidence to suggest Mr. Cordero’s involvement in the grow house operation…Therefore, on the record before us, we must reverse.”

So, there you have it. The state introduces fingerprint evidence. The state gets the jury to convict, but in the end, justice was eventually served by the appeals court. This whole appeal process could have been averted if the trial judge understood the nature of the circumstantial evidence presented in this case. Unfortunately, some trial court judges seem to shy away from dismissing cases in the middle of trial. A mid-trial dismissal is called a “Motion for Judgment of Acquittal”, and the appeals court shared my sentiment when they wrote that a “motion for judgment of acquittal should be granted in a circumstantial evidence case if the state fails to present evidence from which the jury can exclude every reasonable hypothesis except that of guilt.”