Silence is enveloping the Ennis Cosby murder trial.

First, a witness brought from jail took the stand and refused to talk. Then, another man in an orange prison jumpsuit, targeted by the defense as the real Cosby killer, walked back and forth in front of the jury but said not a word.Now, the prosecutor - whose own remarks are nearly inaudible in court - has said that both witnesses wanted to invoke Fifth Amendment protection against self-incrimination.

Eli Zakaria, the silent witness who was displayed to jurors in court, had been expected to tell all about the night Bill Cosby's son was shot.

But prosecutor Anne Ingalls asked him nothing. On Monday, she said she did not question him because his lawyers told her he was going to invoke protection against self-incrimination even if he was granted immunity from prosecution.