When a criminal defendant testifies at trial, the defendant’s trial testimony constitutes a waiver of the privilege regarding the crime at issue. The defendant may not both testify on direct examination and then assert the privilege on cross-examination.
2. Guilty Pleas:
A defendant’s guilty plea is not a complete a waiver of the privilege. If the defendant’s statements can be used against him during sentencing proceedings, the defendant can invoke the privilege, notwithstanding the guilty plea.
A witness does not waive the privilege by taking the stand or by answering non-incriminating questions. However, when a witness answers an incriminating statement, the witness waives the right to invoke the privilege with respect to further questions about that topic. However, if the answer(s) to related questions tend to incriminate the witness in connection with to new or previously undiscussed crimes, the witness may invoke the privilege as to the newly raised matters.