Urie

MEMORANDUM **

Urie appeals his conviction following a jury trial for conspiracy to commit mail fraud in violation of 18 U.S.C. § 371 and conspiracy to commit wire fraud in violation of 18 U.S.C. § 1343 . Urie argues that the district court erred in granting the government’s motion to admit evidence under Fed.R.Evid. 404(b) of an uncharged *610 but similar prior fraud scheme in which Urie allegedly participated. He also argues that the district court erred in denying his motion to present the testimony of an alleged expert witness on Nigerian culture under Fed.R.Evid. 702. Finally, Urie argues for the first time on appeal that the prosecutor engaged in improper conduct during cross-examination and closing argument.

We affirm the district court’s evidentiary rulings, but hold that the prosecutor improperly vouched for the credibility of government witnesses. Because the prosecutor’s misconduct was so prejudicial that it deprived Urie of a fair trial, we reverse the conviction and remand for a new trial.

I. Admission of “other acts” evidence under Rule 404(b)

We review for abuse of discretion a district court’s decision to admit evidence under Fed.R.Evid. 404(b), United States…