What Is Double Jeopardy? Why You Cannot Be Tried Twice for the Same Crime
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A jury finds a man not guilty of murder. A year later a confession surfaces, or a witness comes forward, or DNA is tested that could not be tested before. In most legal systems, for most of history, the answer has been that nothing can be done: he was tried, he was acquitted, and the state does not get a second attempt. The rule is called double jeopardy, it is one of the oldest protections in criminal law, and in the last twenty years several countries have decided it should have exceptions.
An ancient rule
The principle appears in Athenian law, in the Roman maxim that no one should be troubled twice for the same cause, and in the Talmud. In English law it was argued over in the twelfth century between Henry II and Thomas Becket, who objected to clergy convicted in church courts being punished again by the king, and it settled into two pleas a defendant could make: autrefois acquit, that they had previously been acquitted of the charge, and autrefois convict, that they had previously been convicted of it. The Fifth Amendment to the American constitution put it in one clause in 1791: no person shall be subject for the same offence to be twice put in jeopardy of life or limb.
What it protects
The reasons for the rule have been stated many times, most fully by the American Supreme Court in 1957. The state, with all its resources, should not be allowed to make repeated attempts to convict an individual, subjecting them to embarrassment, expense and ordeal and compelling them to live in continuing anxiety, and enhancing the possibility that even though innocent they may be found guilty. Behind that lie several separate concerns:
- •Finality: a verdict must at some point be the end of the matter, or no acquitted person is ever free
- •Equality of arms: a prosecutor who can retry until a jury convicts will eventually find one
- •The integrity of the jury: an acquittal that can be overturned by prosecuting again is not a verdict but an opinion
- •Restraint: the rule forces the state to prepare its case properly the first time
What it does not cover
The rule has always had edges. A mistrial, where the jury cannot agree or the trial collapses, is not an acquittal, and the defendant can be tried again. A conviction overturned on appeal because of a legal error sends the case back for retrial, since the defendant asked for the verdict to be set aside. In federal systems the same act can be a crime under two sovereigns: in the United States a person acquitted in a state court can be tried in a federal court for the same conduct, which is how the police officers acquitted of beating Rodney King in 1992 were later convicted of violating his civil rights. And a civil claim is not a prosecution, so O. J. Simpson, acquitted of murder in 1995, was found liable for the same deaths by a civil jury in 1997 and ordered to pay damages.
The exceptions made
In 1993 a black teenager, Stephen Lawrence, was murdered at a bus stop in south London, and the prosecution of the men suspected collapsed. A public inquiry into the police failures recommended in 1999 that the double jeopardy rule be reconsidered where compelling new evidence emerges, and the Criminal Justice Act 2003 did so for England and Wales: for about thirty of the most serious offences, the Court of Appeal can now quash an acquittal and order a retrial if there is new and compelling evidence that was not available at the first trial and a retrial is in the interests of justice. One of the men acquitted in 1996 was retried under the new law and convicted in 2012. Scotland, Australia and New Zealand have adopted similar rules, and the change is one of the largest to criminal procedure in the common-law world in a century.
The United States has not followed. The Fifth Amendment is read as absolute for the same sovereign, and no new evidence, however strong, allows a federal or state prosecutor to retry an acquittal. Most of continental Europe permits reopening a case in narrow circumstances, and the European Convention on Human Rights protects against double jeopardy while expressly allowing a retrial where new facts come to light or the first trial was fundamentally flawed.
The argument
The case for the reform is that a rule designed to stop oppressive prosecution should not shield a murderer from DNA evidence that did not exist when he was tried, and that an acquittal obtained by intimidating witnesses is not a verdict worth protecting. The case against is that every exception weakens the finality that gives an acquittal its meaning, that new evidence is easy to claim and hard to define, and that a defendant who knows the state may come back is never truly acquitted. Both sides agree on the underlying rule; the disagreement is about how absolute a protection has to be to work.
The takeaway
Double jeopardy is the rule that a person acquitted or convicted of an offence cannot be prosecuted for it again, rooted in Roman and English law and fixed in the American Fifth Amendment, and justified by finality, fairness and the integrity of the verdict. It does not cover mistrials, appeals, civil claims or a second sovereign, and since 2003 England, Scotland, Australia and New Zealand have allowed a retrial for the gravest offences where new and compelling evidence appears, while the United States has kept the rule absolute.