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McDaniel v. Troy Brown, USSC No. 08-559, 1/11/10

US Supreme Court decision

Habeas – Sufficiency of Evidence Review
Evidence submitted well after trial may not be considered in determining sufficiency of the state’s proof under Jackson v. Virginia443 U. S. 307 (1979) …

… An “appellate court’s reversal for insufficiency of the evidence is in effect a determination that the government’s case against the defendant was so lacking that the trial court should have entered a judgment of acquittal.” Lockhart v. Nelson488 U. S. 33, 39 (1988) . Because reversal for insufficiency of the evidence is equivalent to a judgment of acquittal, such a reversal bars a retrial. See Burks v. United States 437 U. S. 1, 18 (1978) . To “make the analogy complete” between a reversal for insufficiency of the evidence and the trial court’s granting a judgment of acquittal, Lockhart, 488 U. S., at 42, “a reviewing court must consider all of the evidence admitted by the trial court,” regardless whether that evidence was admitted erroneously, id., at 41.

Though the Court denies relief, its mention of the “prosecutor’s fallacy” is worth noting:

The prosecutor’s fallacy is the assumption that the random match probability is the same as the probability that the defendant was not the source of the DNA sample. See Nat. Research Council, Comm. on DNA Forensic Science, The Evaluation of Forensic DNA Evidence 133 (1996) (“Let P equal the probability of a match, given the evidence genotype. The fallacy is to say that P is also the probability that the DNA at the crime scene came from someone other than the defendant”). In other words, if a juror is told the probability a member of the general population would share the same DNA is 1 in 10,000 (random match probability), and he takes that to mean there is only a 1 in 10,000 chance that someone other than the defendant is the source of the DNA found at the crime scene (source probability), then he has succumbed to the prosecutor’s fallacy. It is further error to equate source probability with probability of guilt, unless there is no explanation other than guilt for a person to be the source of crime-scene DNA. This faulty reasoning may result in an erroneous statement that, based on a random match probability of 1 in 10,000, there is a .01% chance the defendant is innocent or a 99.99% chance the defendant is guilty.

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