Even if this theory, which is novel, does not result in acquittal, it may persuade the jury to spare Mr. Malvo's life.
"For the second trial to be more serious at all is going to require more rigorous investigation, and that can't be done by the same police force," Mr. Bahgat said, adding that if the second trial sticks to the same evidence as the first, it will almost certainly result in acquittal.
This month, Mr. Medvedev encouraged Russian forces to kill terrorists "without sentiment" and called for an end to jury trials in terrorism cases, which often result in acquittals.
And on the rare occasions when police are put on trial for abuses, he says, cases tend to result in acquittals.
Both excuse defenses and justification defenses can result in acquittals or reduced sentences, but they communicate very different judgments about the acts of the defendants.
But, at a time when trials are often freighted with great political significance, the case, which resulted in acquittal for all the defendants, served mainly to demonstrate the limits of the criminal-justice system.
The issue for the court is whether a variation on the Constitution's guarantee against double jeopardy applies in this situation: The jury votes not guilty on some charges, but fails to reach a verdict on others that are based upon the same essential facts as the charges that resulted in acquittal.
The trial began in 2008, and resulted in acquittal of the two by the ICTY trial chamber on 30 May 2013.
At the federal level, for example, in the most recent data from the 2010 Bureau of Justice Statistics, there were 1,600 federal grand jury cases, of which only 11 resulted in acquittal.
Outrage over a six-month sentence for a Stanford University athlete convicted of assaulting an unconscious woman, and high-profile cases involving Bill Cosby and Roger Ailes have caused many to consider allegations more earnestly, even in a case that results in acquittal.
There have many attempts to tell the O.J. Simpson story, to explain why, in 1995, what appeared to be an open-and-shut case of domestic violence taken to its fatal and too-often inevitable conclusion turned into the trial of the century and resulted in acquittal.
