Court throws out verdict due to math

BOSTON (State House News Service) - A prosecutor’s use of math during a closing argument in a robbery case may have tainted a jury’s analysis, the Supreme Judicial Court ruled Friday, tossing the conviction of a man who was found guilty in 2007 of mugging a 61-year-old pizza deliveryman.

During the trial of defendant Kris Ferreira, prosecutors relied on the deliveryman’s ability to identify two assailants in a series of 12 photographs. One of the prosecutors, during closing remarks, told jurors that the deliveryman’s ability to identify the attackers – even though the deliveryman himself acknowledged he was uncertain he had fingered the correct person – carried a 98 percent chance of accuracy, and he equated that likelihood to guilt beyond a reasonable doubt.

“The issue presented on appeal is whether the prosecutor's mathematical analysis in his closing argument of the probability that the lone eyewitness's identification of the defendant was accurate created a substantial risk of a miscarriage of justice where the analysis was not supported by expert testimony, was fundamentally flawed, and equated proof beyond a reasonable doubt with a statistical probability,” wrote Justice Ralph Gants in a unanimous decision joined by four other justices. “We conclude that where, as here, the prosecution's case rested solely on an uncertain eyewitness identification and the defendant's association with an admitted perpetrator of the crime, it did.”

The case was returned to Superior Court for a new trial.

The attack in question occurred in November 2006, according to facts of the case presented by the SJC. The deliveryman delivered a pizza to a June Street address in Fall River and, as he walked from his vehicle to the house, two men approached him, pushed him to the ground, brandished a knife and demanded that he empty his pockets.

When the deliveryman contacted police and offered descriptions of the men, an officer produced two sets of six photographs of potential suspects. The victim quickly identified one of the suspects – Shawn Pacheco, who later pled guilty to the crime – but hesitated before selecting Ferreira. During the trial, the victim said he was “80 percent sure” that Ferreira was the second attacker but lacked absolute certainty.

During closing arguments, defense lawyers cited this uncertainty to suggest that a jury could not find Ferreira guilty beyond a reasonable doubt. But a prosecutor in the matter noted that the victim not only identified two men who knew each other, but he chose them over a seventh option he had in each set of photos: none of the above.
“Now, let's think about this for a moment. Seven on the left, seven on the right. How many different combinations does that make? By my math, it's forty-nine.... And who does he pick? Bosom buddies,” the prosecutor said, according to the SJC opinion. “The odds of picking two men out of two arrays with forty-nine different combinations who are that type, one out of forty-nine. Two per cent. Two per cent. What are the odds that [the victim] would have picked two different people, some other combination? Ninety-eight per cent. Do you call that coincidence? I call that proof beyond a reasonable doubt.”

In the ruling, Gants called this analysis “false and misleading.”
[W]here the Commonwealth seeks to provide the jury with an analysis of mathematical probability, especially the mathematical probability that an eyewitness identification is accurate, the analysis must be offered through expert testimony, not the prosecutor's closing argument,” he wrote, adding, “The prosecutor also erred in equating proof beyond a reasonable doubt with a numerical percentage of the probability of guilt, in this case, ninety-eight per cent.”

Although the defense attorney made no objection to the prosecutor’s argument, Gants noted, “We conclude that the prosecutor's closing argument error created a substantial risk of a miscarriage of justice because of the danger that the jury gave undue weight to a mathematical probability analysis.”