Spousal vs. Marital privilege

It has come to my attention that many of my friends, as well as a few of my enemies, do not know just when a person can be excused from testifying against their spouse. Accordingly, let me put forward this miniature encapsulation of the matter, which of course is a gross simplification of U.S. federal rules only, is not legal advice, and misses important exceptions that may apply to you and that only a highly paid attorney could tell you about.

The first thing to note is that there are two separate privileges that may come into play. First is the individual right of a person not to testify against their spouse. This right is the "property" of that individual, and only comes into play if the individual is called as a witness in a criminal matter to testify against their defendant spouse. If these circumstances are present, the law imputes the "one flesh" concept to the 5th Amendment and considers having to testify against your spouse the same as testifying against yourself. This protection covers not only what the witness has observed during the marriage, but also what was observed or known about the individual at any time before the marriage. Note that this only applies to a current spouse, so if the marriage ends or is not valid for any reason, it will no longer protect the witness.

The second type of privilege is marital. It comes about because of the special relationship of marriage, and bears analogy to the attorney-client privilege. Its purpose is to allow spouses to freely communicate without worrying about whether their communications will come out in court, and so is held by both persons and can be individually exercised by either to silence (for purposes of legal evidence) the other. It is valid in both civil and criminal contexts, and covers communications and observations that are sufficiently "marital" (sometimes a tricky test). It only covers those things that occur during a valid marriage, but can be used after the marriage is over to maintain the silence.

To illustrate all this, if a divorcee is the defendant in a criminal case and both his current wife and his former wife are called by the prosecution to discuss things the defendant had done in their presence, the current spouse could say, "I refuse to testify" and be excused completely. The former spouse, however, could not excuse herself, but the defendant could forbid her to discuss those things that had been done during the marriage. This would be true regardless of whether the former wife actually really wanted to testify against him.