An acquittal in a criminal case means that the prosecution failed to prove its case beyond a reasonable doubt. It does not represent a finding that the defendant (accused) is innocent. An acquittal occurs in a criminal trial when a defendant is found not guilty by a judge or jury. After an acquittal, the constitutional prohibition against Double Jeopardy prevents further prosecution of the defendant for the same crime, even if new evidence is discovered.
Additionally, an acquittal cannot be appealed except under one rare exception (see, Harry Asleman v. Judges of the Criminal Division, Circuit Court of Cook County, Illinois, et al., F.3d 302 (7th Cir. 1998)), where the court held that Double Jeopardy does not apply when a defendant is acquitted by a bribed judge – in other words, under those circumstances, a defendant can be reprosecuted. An acquittal does not prohibit the filing of a civil action against the defendant on the same set of facts.
For example, after O.J. Simpson was tried and acquitted of murder, the families of the victims successfully sued him in civil court for Wrongful Death. If you or someone you know is facing criminal charges, consult with an experienced criminal defense attorney to learn about the probability of obtaining an acquittal at trial, or the pros and cons of a plea agreement.