Before the trial, the judge cited marital privilege and other laws and ruled the prosecution couldn't ask Ms. Mangan-Valle if she thought Mr. Valle really planned to carry out the plot to kidnap and murder her.

WSJ: Accused Cop's Wife Testifies About Alleged Cannibal Plot

Hiram Eastland, a lawyer representing former Espy aide Ron Blackley, says Smaltz's lawyers put Blackley's wife on the stand and tried to get her to testify against her husband despite the long-standing marital-privilege doctrine.

CNN: The Peril Of Prosecutorial Passion

Tax experts say one of the biggest issues that comes up quickly among Americans is the so-called unlimited marital-deduction privilege.

WSJ: Legal Hassles of Global Love Affairs | WSJ.Money Summer 2013