I understand that the court cannot force a person to testify against a spouse, but does marital privilege prevent a person from testifying against their spouse?
No, a spouse has the right to testify if she so desires.
If this weren’t the case, it would make domestic violence cases basically impossible to enforce.
No, not necessarily. Many Domestic Violence convictions are obtained even without the testimony of the victim, or indeed when the victim is supporting the accused, a distressingly common scenario
To the OP, is not barred, in most jurisdictions that I know of…
From what I’ve seen divorce, domestic violence, custody type cases are exempt.
Supposed a husband tells his wife he killed someone, she agrees to testify against him, can the court stop her or can the defense throw out her testimony?
If I recall correctly, this is a minority position among US states. In most states, the rule is that the spouse who is a party to the lawsuit holds the privilege and can prevent the other spouse from testifying.
In general, exceptions exist for civil cases between the spouses (such as divorces) or criminal cases alleging a crime by one against another (such as domestic violence).
It varies from jurisdiction. In Canada, the spouse can choose to testify, over the other spouse’s objection.
There are two types of marital privilege. The first has to do with communications within the marriage. “Honey, I killed the neighbor.” This type of testimony is generally prohibited whether the spouse wants to testify or not.
The second type is witness testimony. The wife observes the husband killing the neighbor. Generally in this situation, the wife may choose to testify or not, however some states hold on to the old rule that even if she wishes to testify she may not.
These laws vary by state and have exceptions for violence against each other or abuse towards the children.
This is true in California – there is a privilege for confidential marital communications, and a privilege not to testify. There are tons of exceptions (see the code), but that’s the general outline.
So a court can (mostly) not compel (or force, as the OP says) a person to testify against his spouse, unless it’s one of the listed exceptions. For example, domestic violence is a listed exception – if the spouse is charged with a crime, there’s no privilege. Cal. Evid. Code s 972(e)(1).
And the privilege for marital communications is only for things SAID during the marriage. So if the wife sees the husband kill their kid, she can testify about it (because (a) she’s not testifying about a communication, but about actions she witnessed and (b) there’s an exception for testifying in certain criminal cases, like murder of their kid).
It can be a sticky area, but interesting to think about.
I see two types of potential communications privileges. One is if a person is called to the stand and asked to testify about something their spouse said, whether the person called can refuse on the grounds of marital privilege. The other is whether or not someone (person 1) can forcibly shut their spouse up (person 2) from testifying on the stand about something person 1 said even if they (person 2) want to reveal it.
E.g.
Scenario 1:
Attorney: “Did your spouse tell you anything about the Granola account?”
Witness: “I refuse to answer that question on the ground of spousal privilege.”
Scenario 2:
Attorney: “Did your spouse tell you anything about the Granola account?”
Witness: “Well, they said that they had called Jones <gets cut off>”
Spouse: “Objection, your honor! I’m the witness’s spouse and I claim spousal privilege. Put a sock in their mouth before they say anything more that I don’t want revealed!”
And about being forced to testify when the spouse is accused of a criminal offense?
Whatshername married Christopher in The Sopranos for that reason, to keep him covered, but I think she had it wrong, like many people (including me).
In (almost) every U.S. jurisdiction, the communications during the marriage are sacrosanct. The spouse cannot be forced and may not if he/she chooses testify about them.
If the spouse witnesses a crime committed by the other spouse, in (almost) every state, the spouse may not be forced to testify as to what he/she saw. The states are split on whether the spouse may voluntarily testify as to what he/she saw. Some leave that choice with the witness-spouse, others hold it is a privilege of the accused.
The marital privilege extends to criminal offenses as well (except, as has been said, crimes against each other or the children). The communication privilege only applies to communications during marriage. Pre-marital communications would be treated just like the state’s rule for testimonial privilege.
This is a handy list you can refer to when your studies direct you there. Sometimes the SC has a handy dandy state list in thier rulings, at FN 9; of course current law needs to be looked up, as it is a 1980 list;
State’s listed after each headnote;
Eight States provide that one spouse is incompetent to testify against the other in a criminal proceeding:
Sixteen States provide a privilege against adverse spousal testimony and vest the privilege in both spouses or in the defendant-spouse alone:
Nine States entitle the witness-spouse alone to assert a privilege against adverse spousal testimony:
The remaining 17 States have abolished the privilege in criminal cases: