United States v. Vavages

United States Court of Appeals for the Ninth Circuit · 1998 · Evidence

151 F.3d 1185 (9th Cir. 1998)

Updated August 22, 2026

Evidencedue processdefense witness intimidationperjury warningsFifth Amendmentcompulsory processwitness coercionprosecutorial misconduct

Facts

Before trial, Vavages disclosed that Rose Marie Manuel, his common-law wife, would testify in support of his alibi that he was at home when a marijuana-filled car registered to him was stopped and its occupants fled. After learning Manuel had her own unrelated marijuana case with a plea agreement, the prosecutor told Manuel's attorney that he believed Vavages' alibi was false and warned that if Manuel testified falsely, the government could prosecute her for perjury and withdraw from her plea agreement. Manuel then invoked the Fifth Amendment and did not testify, and the district court accepted her blanket invocation based on her fear that testifying would expose her to perjury charges. In closing, the prosecutor emphasized that no adult witness supported Vavages' alibi other than his children.

Issue

Whether the prosecutor's warnings and threats substantially interfered with Manuel's free choice whether to testify, thereby violating due process and prejudicing Vavages' defense. Also, whether the district court erred by accepting Manuel's blanket Fifth Amendment invocation when it was based only on fear of a perjury prosecution arising from her anticipated testimony.

Rule

Substantial government interference with a defense witness's free and unhampered choice to testify violates due process. Perjury warnings are not improper per se, but constitutional rights are implicated when a prosecutor or trial judge uses coercive or intimidating language or tactics that substantially interfere with the witness's decision whether to testify; relevant considerations include the manner of the warning, its language, and whether the prosecutor had a substantial basis in the record for believing the witness might lie. A witness cannot validly invoke the Fifth Amendment merely from fear of a future perjury prosecution based on the testimony the witness is about to give, because the protection against that risk is to testify truthfully.

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One of 10 multiple-choice questions for this case. Pick an answer to see why.

In a federal robbery trial in Phoenix, the defense plans to call Lena Ortiz to testify that Devin Cross was at her apartment when the robbery occurred. The prosecutor tells Lena's lawyer that if Lena gives that alibi, the prosecutor considers it false and will pursue perjury charges, even though Lena has previously given the same account to investigators. Lena then refuses to testify.

If Devin argues that his due process rights were violated, what is the strongest basis for that claim?

Explanation. Due process is violated by substantial government interference with a defense witness's free and unhampered choice to testify. Perjury warnings are not improper per se, but they become unconstitutional when coercive or intimidating. A key factor is whether the prosecutor had a substantial basis in the record for believing the witness would lie. Here, the witness's proposed testimony was consistent with her prior statements, so merely contradicting the government's case was not enough. Speaking through counsel does not avoid a violation if the warning was a but-for cause of the witness's refusal.