SoM Professor Called to Give Expert Testimony in Jury Selection Case

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Prof Michael Lacey of the SoM has been called to be a expert witness in a recent case where prosecuters in several capital crime trials have been accused of striking black jurors discrimenently. We had a chance to speak with Michael Lacey about this very important case, and this is what he said.

Potential reasons to strike a juror are manifold, influenced by a number of considerations. Under ideal circumstances, the reasons for striking a juror should be generally race neutral. Namely the reasons for striking a juror should be as prevalent in the pool of qualified white jurors as in the pool of black jurors. Put differently, knowing that a juror is struck should give us very little information about the race of the struck juror.

In a jury trial, there is a pool of jurors which are selected randomly from the county in which the trial is to take place. The lawyers on each side have a certain number of strikes, which they may use to remove potential jurors from the pool. Whomever is left after all the strikes are used are the jurors which will sit on the trial.

In the cases under question, Prof Lacey was called to determine if the likelihood of an all white or nearly all white jury was statistically probable given the potential jury pool in each case.

Prof Lacey uses a deck of cards and elementary counting principles to illustrate the likelihood that all of the potential black jurors in a jury selection pool are struck.

We have a deck of 48 cards, 4 of which are Red Ace cards. Draw a
hand of 12, which are the 12 strikes by the prosecution. If the hand
of 12 contains all 4 Red Aces, then the prosecution has struck all 4
qualified black jurors. These are the sorts of probabilities that a poker
player would be well acquainted with. They are easy to calculate, and
part of a standard course in statistics.

In the seven cases under question, each jury that went to trial was deemed statistically unlikely to occur for race neutral reasons. Taken together, the likelihood that the jury selection process occurred for race neutral reasons was astronomically small, Prof Lacey says.

The likelihood of the seeing these outcomes in the jury selection is approximately the chance of winning the Powerball Lottery three successive times, purchasing only one ticket with each play.

For more reading about the cases see the recent article in the Atlanta Journal-Constitution:



  • Workflow Status: Published
  • Created By: sbarone7
  • Created: 03/30/2018
  • Modified By: sbarone7
  • Modified: 03/30/2018


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