1. Whether excluding expert testimony on eyewitness memory and police lineup procedures violates the Sixth Amendment right to present a defense, or constitutes an abuse of discretion under Rule 403, when eyewitnesses must identify a stranger, no substantial independent evidence corroborates identification, and expert testimony is the sole defense?

2. Whether the government violates Brady v. Maryland and the Fifth and Sixth Amendment rights to due process and cross-examination by withholding ex parte arrests, detentions, court hearings, and government contacts, it used to secure eyewitness trial testimony, and whether a defendant is entitled to an evidentiary hearing to determine whether the government's activities materially affected eyewitness credibility, when defendant learns about suppressed information on appeal?

Whether excluding expert testimony on eyewitness memory and police lineup procedures violates the Sixth Amendment right to present a defense, or constitutes an abuse of discretion under Rule 403