I think it depends on circumstances and the Country and time you live in? Pretty sure that laws have changed or evolved over time. For example in some places and times, in relation to privilege, it had been against the law to report somethings you know, depending on how you found out ie confession from client or church member but now it is more likely to be required to report in most countries. My current understanding anyway.



https://www.law.cornell.edu/wex/attorney-client_privilege

Attorney-Client Privilege

https://www.law.cornell.edu/wex/spousal_immunity

Spousal immunity

https://en.wikipedia.org/wiki/Priest%E2%80%93penitent_privilege

Priest–penitent privilege

The clergy–penitent privilege, clergy privilege, confessional privilege, priest–penitent privilege, clergyman–communicant privilege, or ecclesiastical privilege is a rule of evidence that forbids judicial inquiry into certain communications (spoken or otherwise) between clergy and members of their congregation. The law recognizes certain communication as privileged and not subject to otherwise obligatory disclosure; for example, this often applies to communications between lawyers and clients. In many jurisdictions certain communications between a member of the clergy of some or all religious faiths (e.g., a minister, priest, rabbi, imam) and a person consulting them in confidence are privileged in law. In particular, Catholics are required to confess sins to priests, who are unconditionally forbidden by Church canon law from making any disclosure,^[1] a position supported by the law of many countries, although in conflict with civil law in some jurisdictions.^[1] It is a distinct concept from that of confidentiality (see non-disclosure agreement).

The protection of the clergy–penitent privilege relationships rests on one of the more basic privileges as strong or stronger than the similar clauses to confidentiality between lawyer and client.^[2]

 

If you are in an area controlled by the Mafia or other illegal organisation, you may well find that the gang punishments are more severe than those imposed by the authorities, assuming the latter can find sufficient witnesses to support their case. 

In theory, you may be abetting the crime; in practice, charges may not stick particularly if the criminals have friends in court. 

Your status would be more akin to that of a hostage. 

 

 

No, provided that you're not a party to that crime and have not "officially" been called before the Bar, unless you're an attorney or a jurist. Being a member of the Bar ethically binds members to a higher standard than we mere mortals and their failure to report/testify would be an ethics violation that could lead to disbarment for the lawyer or impeachment for the jurist. But if you don't tell anyone then how is anyone going to know that you have knowledge of the crime in question?

If you have been called before the Bar (a subpoena had been issued by the Court for you to appear and testify) then you are generally compelled to do so or possibly face being charged with Contempt. There may be ways to avoid testifying like trying to invoke your 5th Amendment Rights at that point. But unless you've been charged with the crime in question as well the judge won't consider it in the first place; doing so is only applicable to avoid testifying against yourself, not against others. So unless you've been charged you're still looking at that Contempt charge. Probably best to fall back on your failing eyesight, lousy hearing and poor memory at that point if you do want to avoid your civic duty for some reason.  

And those exceptions noted above . . . attorney/client privilege only applies if you're an attorney acting as council to someone else involved in the case and you had no prior knowledge of the crime. If your client does confess involvement to you AFTER retaining your services then you generally can't divulge that confession to the Court without committing an ethics violation unless your client gives consent. (If you did have prior knowledge you can't act as council in the first place and may already be in deep tapioca for not bringing what you know to the attention of the Court, see my first paragraph.)

The "Confessional" testimony, mainly applying to the Catholic Church, is strongly governed by Canon Law, and the Church follows that law religiously (pun intended). Any priest that ignores that is subject to excommunication from the Church. But so far as I know there's no secular legal penalty for the Priest should he chose to ignore that Confessional Seal.  Just make sure that your tithing's to the Church's building fund are up to date. And another gray area there is what if someone else in line for Confession overhears what is being said in the Confessional? Best to just keep your nose clean.

And the "Spousal Immunity" thing . . . that can be invoked at the pleasure of the spouse to be questioned, but they have no obligation to do so. The spouse just can't be compelled to testify nor can any information obtained from them if they do invoke that Right be used in Court. But they can certainly take the stand an spill their guts should they so chose. Best to not tick off your spouse during trial proceedings if you're involved . . .