How have the courts treated improper statements by a prosecutor?

Although we do not include a full recitation of the statements claimed to be improper, they can be broken down into roughly three categories: statements that allegedly mischaracterized the evidence,¹⁷ statements that allegedly reflected the prosecutor's personal beliefs about defense counsel,¹⁸ and statements that allegedly denigrated the defense expert.¹⁹ Upon careful review of the record as a whole, we find that most of the comments were permissible arguments about the merits of the defendant's theory of the case or made in response to defense counsel's own summation comments, which impugned the integrity of the government's case. See United States v. Carr , 424 F.3d 213, 227 (2d Cir. 2005) ([T]he government is allowed to respond to an argument that impugns its integrity or the integrity of the case, and when the defense counsel have attacked the prosecutor's credibility or the credibility of the government agents, the prosecutor is entitled to reply with rebutting language suitable to the occasion. (internal quotation marks omitted)). In any event, even assuming that some of the statements made by the prosecutor were improper, they certainly cannot be considered to amount to flagrant abuse. See Farhane , 634 F.3d at 167 (The law has long recognized that summationsand particularly rebuttal summationsare not detached expositions, with every word carefully constructed before the event. (alterations and internal quotation marks omitted)). As the district court observed, although some of the prosecutor's statements were not as nuanced as the power of hindsight in a non-summation context would permit, A. 252-53, none of the statements were so egregious that, even when taken cumulatively, they could have undermined the fairness of the trial.