argued.” ABA Standards for Criminal Justice, Commentary, at 3.89. The Supreme Court has observed that a prosecuting attorney’s “improper suggestions, insinuations, and especially, assertions of personal knowledge are apt to carry much weight against the accused when they should properly carry none.” Berger v. United States, 295 U.S. 78, 88 (1935).
However, our finding that the prosecutor’s comments were improper does not end the inquiry. Since defense counsel did not object to the prosecutor’s remarks, we must determine whether the prosecutor’s misconduct constituted plain error which affected substantial rights of the defendant. Hawaii Rules of Penal Procedure, Rule 52(b).
We think the prosecutor’s improper comments, taken as a whole, substantially prejudiced Marsh’s right to a fair trial. The pivotal issue was the credibility of the witnesses. The jury had to decide whether to believe the victim or the alibi witnesses. We cannot conclude beyond a reasonable doubt that the prosecutor’s remarks had little likelihood of influencing this critical choice. See United States v. Garza, 608 F.2d 659 (5th Cir. 1979). Cf. State v. Churchill, 4 Haw. App. 276, 664 P.2d 757 (1983).
We cannot accept the State’s argument that the prejudicial impact of the remarks was rendered harmless by the trial court’s instructions to the jury. The effect of the prosecutor’s prejudicial conduct here overcomes the presumption that the court’s instructions to the jury rendered it harmless. Cf. State v. Kahalewai, 55 Haw. 127, 129, 516 P.2d 336, 338 (1973). The trial court instructed the jurors several times that the arguments of counsel are not evidence. However, the court was not requested to and did not issue a specific instruction concerning the prosecutor’s closing comments.2
In light of the inconclusive evidence against Marsh, the particularly egregious misconduct of the prosecutor in presenting her personal views on the dispositive issues, and the lack of a prompt jury instruction specifically directed to the prosecutor’s closing remarks, we hold that the prosecutor’s conduct so prejudiced Marsh’s right to a fair trial as to amount to “plain error.” The conviction is reversed and the case is
2
It should be noted that the trial judge has an obligation in the interests of fairness and justice to stop the prosecutor from delivering a greatly prejudicial argument sua sponte. See Viereck v United States, 318 U.S. 236 (1943).