Reversal was required here where a prosecutor knowingly used false testimony during trial. During a prosecution for making false statements to a bank to obtain a loan, the prosecutor knew that the loan officer, who identified a key witness at trial, had previously testified that he did not recognize her. The prosecutor did nothing to correct the false impression of the facts left with the jury, and in fact, attempted to bolster the witness’s credibility during argument, though he conceded during rebuttal argument that the witness had lied. Defense counsel was ineffectual in his attempt to impeach the witness. Reversal was required because the use of known lies to obtain a conviction deprived appellant of his constitutional right to due process of law. There was a reasonable likelihood that the false testimony affected the outcome. The case was close, and it was the third trial following a hung jury. The witness who was falsely identified was a critical actor. The prosecution’s eventual admission of the lie occurred after the defense had finished its last chance to speak, and therefore did not cure the error.