The Constitution prevents a person from being tried more than once for the
same crime. Jeopardy does not attach until there is a jury verdict or a
dismissal with prejudice by the judge. If there is a mistrial because of attorney
misconduct or because the jury cannot reach a verdict, then there is no final
ruling and the prosecutor may retry the case. Generally, the prosecutor may
only try the defendant once on a given set of facts. If the defendant is found
innocent of murder, he or she cannot be retried on the same facts for a lesser
included offense such as manslaughter.
Double jeopardy only applies to one level of government. If the state tries a
person for murder and the defendant is acquitted, the federal government can
retry the person on the same facts, perhaps for civil rights violations. This is a
significant problem in medical care because many of the prohibited activities,
especially fraudulent transactions, violate both state and federal law.