Trammel v. United States 445 U.S. 40, 100 S.Ct. 906, 62 L.Ed.2d 186 (1980) Trammel and two other guys were arrested and charged with drug smuggling. Trammel's wife was listed among the unindicted co-conspirators. Trammel's wife had also been arrested in possession of drugs, but had agreed to testify in exchange for immunity. At trial, when his wife took the stand to testify, Trammel objected on the grounds that her testimony was not admissible because it was protected by spousal privilege. The Trial Judge allowed her to testify to any act she observed during the marriage and to any communications made in the presence of a third person.  However, confidential communications between Trammel and his wife were inadmissible because of spousal privilege. Historically, there were two different types of spousal privilege: Spousal Testimonial Privilege said that a spouse could never testify against the other spouse on any issue, as long as they were married. Once the marriage was over, this bar was lifted. Spousal Communications Privilege said that a spouse could never testify about communications between the two made during the marriage, even after they got divorced. The Trial Court convicted Trammel of drug smuggling.  He appealed. The Appellate Court affirmed.  Trammel appealed. The Appellate Court found that the spousal testimonial privilege did not prohibit voluntary testimony of a spouse who appears as an unindicted co-conspirator under a grant of immunity. The US Supreme Court affirmed. The Court noted that the leading case was Hawkins v. United States (358 U.S. 74 (1958)), which followed the common law tradition that one spouse cannot testify against the other unless both consent. Under Hawkins, all testimony by the spouse was inadmissible.  This was much broader than other privileges (like lawyer-client), which only applied to confidential communications. However, the Court also noted that under FRE 501, the courts have the authority to continue the evolutionary development of privilege rules. The Court found that the spousal testimonial privilege rule should be similar to other privileges.  The spouse is not barred from testifying if they chose to do so.  However, they cannot be compelled to do so. Basically, the testifying spouse is the only one who can raise the issue of privilege.  If they want to waive it, the accused spouse can't stop the testimony. Currently, the spousal communications privilege may be asserted by either spouse in both civil and criminal proceedings; the spousal testimonial privilege may only be claimed by the testifying spouse, and is only recognized in criminal proceedings.