The 5th amendment protects people from being force to testify to things that would incriminate themselves. But what would happen if someone tried to abuse the priviledge?
Say, for instance, that I didn’t want to testify against a friend or significant other in an assault case or other a minor crime. What would happen if, when asked what I was doing or what I saw, I claimed that testifying would incriminate myself? Could they compel me to testify? What would happen if I was found out?
You’d be held in contempt of court.
One could always develop selective amnesia and not recall the events in question.
They could also grant you immunity, which would strip you of your 5th amendment protection (because now they can’t prosecute you if you do incriminate yourself). They would be unlikely to do this unless they already knew what your testimony would be.
One common tactic is to grant you immunity, then the 5th doesn’t apply. The feds did this with Sam Giancana. He still refused to testify, was jailed for contempt, ended up in a Mexican jail (long story) and then after returning back to Chicago was killed.
The reasons he refused to tesify after immunity probably included not wanting to be killed by the people he would testify against (which didn’t seem to make a difference in the long run) as well as the general code of silence thing.
If it becomes questionable (like why would you incriminate YOURSELF if you talked about what your buddy did?) then the judge will talk to you (and your lawyer if you have one) to see exactly what you would be doing to incriminate yourself.
In this “off the record” conversation you have to convince the judge, who has a very good bullshit detector in his head, that you are TRULY concerned about your own interests…