Massachusetts Criminal Defense Lawyer Blog

The Massachusetts Court of Appeals in the case of Commonwealth v. Ferreira, decided September 14, 2010, held that the prosecutor's mathematical argument regarding reasonable doubt was an improper closing argument. During the Massachusetts criminal defense lawyer's closing argument, counsel argued that the victim stated that the victim was 80% certain that the defendant committed the criminal offense of unarmed robbery. The prosecutor argued that the victim had a good opportunity to see the defendant and picked the defendant and a co-defendant out of a 49 person line up. The prosecutor responded that the odds of the victim picking two men out of a 49 person line up is 98%. The prosecutor argued that was proof beyond a reasonable doubt.

The Massachusetts Appeals Court emphasized that under Massachusetts criminal law it is not enough for the prosecution to establish a probability, though a strong probability as reasonable doubt requires the Commonwealth to prove its case to a reasonable and moral certitude. The court emphasized that reasonable doubt is not capable of being defined mathematically and that selecting a defendant from a photographic array is not the same as selecting cards from a deck. When a Massachusetts criminal defense lawyer makes an argument alleging an improper closing argument by the prosecutor, the violation is of the defendant right to a fair trial and due process of law under the United States Constitution and the Massachusetts Declaration of Rights.

Despite the court finding the argument to be improper, the court declined to reverse the conviction finding that the error did not cause a substantial risk of miscarriage of justice. In a dissenting opinion, Justice Milkey, argued that he would reverse the conviction finding that the prosecutor's closing argument created a substantial risk of miscarriage of justice and characterized the prosecutor's mathematical proof as a nonsensical argument that was superficially powerful but ultimately improper under long standing case law in Massachusetts. Justice Milkey emphasized that courts have cautioned against the use of mathematical proof in criminal trials as it can confuse the jury and have the aura of scientific evidence. Further, the Justice reviewed the mathematical assumptions of the prosecutor and argued that the reasoning made little sense as the odds of a victim selecting a photograph from an array are not the same as the odds of the victim being correct. Additionally, the justice stated he would reverse the conviction because the Commonwealth had a relatively weak case and the error may have created a substantial risk of miscarriage of justice. It is likely that the defendant will seek further appellate review in the Massachusetts Supreme Court. I would expect the court to grant review.