I have a friend who was in jail when a seperate inmate, recently arrested for murder, decided to approach my friend and confess all the details about the entire gruesome murder he and his friend just enacted. Completely mortified, shocked and in a sick disbelief, he mentioned to another that this guy just came up to him and confessed (he didn’t go into detail). Anyway, a guard overheard this and the next day detectives were there to pay my friend a visit, wanting to know what was said. Unsure of what to do he mentioned a few things the inmate had stated and it was enough information, not yet known to the public, to convince the detectives this was the real deal. Bottom line: my friend has testified in a preliminary court hearing and believes after a variety of incidents he has not been given approprate protection from the state, thus causing him to change his mind and not testify, to protect his family and himself. Can he take the fifth? Oh I forgot to mention, the defendent accused of murder is a gang member. Please help? 
I’m going to move this to General Questions . . . lordamercy, what a terrible situation!
My hopes for a good resolution to your friend and his family.
your humble TubaDiva
Administrator
Does he have a lawyer? He should get one, pronto, to find out the extent of protection and to negotiate for witness protection.
As I understand it, he cannot take the Fifth. The Fifth is a privilege against self-incrimination, but the evidence which your friend could give would not incriminate your friend with anything.
If subpoenaed, he cannot refuse to testify and, if he does, he is in contempt and is liable to imprisonment or other penalties.
However that won’t help the prosecutor. The prosecutor wants your friend to testify, not to go to prison for refusing to testify, so there is a basis for a deal; the prosecutor delivers enough in the way of protection to persuade your friend to testify. Your friend has an incentive to deal, as well; the gang member concerned may already know that he has spoken to detectives, so even if he give no further evidence he may still feel in danger, and in need of protection. Which he won’t get, unless he testifies.
He should get a good criminal laywer, now, and approach the prosecutor to outline his extreme reluctance to testify.
IANAL, but I have seen enoughg TV shows to know that your friend has the makings of a deal.
Lawyer, lawyer, lawyer, lawyer, lawyer, lawyer, lawyer, lawyer!
I’m no particular fan of some aspects of the profession, but if your friend is looking at a choice between being sent to prison for refusing to testify or being shived in the parking lot outside the courthouse then he might want to seek some advice from a source with a little more professional standing than an internet chat board. You’ll get some great, very learned discussion here of general legal obligations to testify, but these things can so often turn on the peculiarities of the case. Your friend needs to be advised by someone who is completely familiar with both the law in his jurisdiction and his particular circumstances.
Your friend is in need of legal advice and the SDMB’s are NOT the place to seek it.
Your friend has received information of interest to the prosecutor.
That said, the court may not accept it since it is second hand and therefore hearsay.