The law of closing arguments in criminal cases has proven to be a minefield for prosecutors and judges. Whereas criminal convictions can be overturned because of improper argument by the government, acquittals obtained through improper argument by defense counsel cannot be reviewed because of the Double Jeopardy clause. Two rules, the prohibition against vouching and the proscription against the expression of personal opinions, have proven to be very difficult to apply in a coherent manner, to the point that argument about the credibility of witnesses has been prohibited in some jurisdictions. Jury nullification arguments by the defense tend to creep into a criminal trial during summation, and they present a difficult dilemma for the ethical prosecutor. Sometimes error in closing argument occurs when the prosecutor attempts to respond to appeals for jury nullification, that is, for a verdict outside the law and the evidence presented in the courtroom. An effective means of policing closing arguments and of preventing jury nullification would be a rule that requires closing arguments to mirror the trial. This “mirroring” principle means that the scope of closing argument should be the same as the scope of the facts and law presented during the trial. This principle would set out logical boundaries of proper and improper argument, and it would help trial judges identify and thwart pleas for jury nullification.
Alex J. Grant, CRIMINAL LAW—MIRRORING THE TRIAL: MAKING SENSE OF THE LAW OF CLOSING ARGUMENT IN CRIMINAL CASES, 41 W. New Eng. L. Rev. 7 (2019), https://digitalcommons.law.wne.edu/lawreview/vol41/iss1/2