Manifest Necessity (Double Jeopardy)

The concept of double jeopardy is straight-forward enough.  The aim is to prevent prosecuting a person for the same offense twice. The questions testing this topic on the MBE can be difficult, though. And one term you should be sure to know in this context is "manifest necessity."

A verdict in the first case is not required for double jeopardy to apply. Sometimes, but not always, a mistrial will be the equivalent of a verdict. And whether a mistrial is the equivalent of a verdict will depend upon whether the first trial ended due to manifest necessity.

Importantly, if the first trial ends due to manifest necessity, then the mistrial will not act as a bar to a later prosecution on the same offense. In other words, double jeopardy will not apply. If the first trial does not end due to manifest necessity then the second trial on that same offense will be barred by double jeopardy. So, this idea of manifest necessity is essential in the analysis.

There are some common fact patterns on the MBE. If a defendant requests a mistrial and the judge grants it, this will almost always be considered manifest necessity and the defendant can therefore be retried later. If the judge decides that jurors have been unfairly prejudiced and that this prejudice requires that the trial be terminated, that termination will almost always be deemed to have been caused by manifest necessity and so once again double jeopardy will not act to bar the defendant from being retried. If, on the other hand, there is a mistrial because a necessary witness for the prosecution fails to appear then that mistrial is likely to be deemed not caused by manifest necessity and double jeopardy will likely bar the defendant from being retried on that same offense.

A question on the MBE had a judge granting a mistrial because a close relative of the judge died and the judge could no longer continue on as planned to hear the case. Courts here, in determining whether this amounts to manifest necessity, are likely to balance some factors. But on the MBE question, the court held that there was no manifest necessity for that mistrial (for example, the judge could have sought to have another judge appointed) and as such the double jeopardy clause barred a second trial. The defendant could not be retried on that offense.