More often than not, the defendant in a criminal trial is advised by his attorney not to take the witness stand because the defendant would have to face cross-examination by the prosecutors.
But lets assume the defendant decides to testify. He is asked favorable questions by his defense attorney and makes a good impressions upon the jury. Next up would be the cross-examination.
What happens if the defendant from this point on remains silent and refuses to answer any further questions, first and foremost by the prosecution?
What would be the legal ramifications? The defendant still has his 5th amendment rights, or does he?
He gives up his 5th amendment right by taking the stand in his own defense. He is held in contempt of court for not answering questions. Contempt of court is a criminal charge, in and of itself, which can carry jail and/or a fine.
He would be found in contempt for refusing to answer. Her does still have his 5th Amendment rights, but he must speak in order to use them. And that doesn’t stop him from having to answer non-incriminating questions, like “what is your name?”
The Judge would likely hold him in contempt, and slowly up the ante with punishment to induce the defendant to answer. I imagine the judge would sit the guy in a jail cell until he felt like answering some questions.
IANAL - I would imagine his selective silence now can be considered by the jury as part of the evidence. “He said A but refused to explain further detail when asked”.
The jury is only instructed that they cannot take into account that a defendant has declined to take the stand. Once he does, the entirety of his answers or lack are open to interpretation.