Prosecution’s use of the defendant’s silence
A savvy prosecutor will attempt to use a defendant’s silence, in circumstances where an innocent person could be expected to speak, as substantive evidence of guilt in his case in chief or as impeaching evidence during cross-examination of the defendant.
The constitutional limits on the use of the defendant’s silence vary, depending on the time period of the silence: before arrest; after arrest, but before Miranda warnings are given; after arrest and after Miranda warnings have been given.
The prosecution may introduce evidence of the defendant’s pre-arrest silence upon cross-examination of the defendant. Whether it may be used as substantive evidence without violating the Fifth Amendment privilege against self-incrimination is unclear.
Even in a jurisdiction that permits the use of the defendant’s pre-arrest silence in the prosecution’s case in chief, a skilled criminal defense attorney may be able to keep it out. The attorney can argue that the silence lacks any probative value. In other words, it proves nothing so it is irrelevant. Judges sense the unfairness of using against a defendant the silence that is his or her right so may agree and refuse to let the defendant’s silence into evidence.
Post-arrest, pre-Miranda silence
A post-arrest, pre-Miranda silence may be used to impeach the defendant on cross-examination if he or she testifies. However, courts disagree on whether the prosecution may introduce the silence as substantive evidence in its case.
Post-arrest, post-Miranda silence
Since Miranda warnings promise that silence is without cost, the Due Process Clause prohibits any use of such silence, even to impeach the defendant.
However, the prosecution can introduce evidence of the defendant’s picking and choosing which questions to answer and which not to answer.