Perry Juvenile Law Lawyer, Ohio

Latin for a 'guilty act.' The actus reus is the act which, in combination with a certain mental state, such as intent or recklessness, constitutes a crime. For example, the crime of theft requires physically taking something (the actus reus) coupled with the intent to permanently deprive the owner of the object (the mental state, or mens rea).

A mental defect or disease that makes it impossible for a person to understand the wrongfulness of his acts or, even if he understands them, to ditinguish right from wrong. Defendants who are criminally insane cannot be convicted of a crime, since criminal conduct involves the conscious intent to do wrong -- a choice that the criminally insane cannot meaningfully make. See also irresistible impulse; McNaghten Rule.

A trial that ends prematurely and without a judgment, due either to a mistake that jeopardizes a party's right to a fair trial or to a jury that can't agree on a verdict (a hung jury) If a judge declares a mistrial in a civil case, he or she will direct that the case be set for a new trial at a future date. Mistrials in criminal cases can result in a retrial, a plea bargain or a dismissal of the charges.

A rule of evidence that disallows the use of illegally obtained evidence in criminal trials. For example, the exclusionary rule would prevent a prosecutor from introducing at trial evidence seized during an illegal search.

(1) To discredit. To impeach a witness' credibility, for example, is to show that the witness is not believable. A witness may be impeached by showing that he has made statements that are inconsistent with his present testimony, or that he has a reputation for not being a truthful person. (2) The process of charging a public official, such as the President or a federal judge, with a crime or misconduct and removing the official from office.

Latin for 'we shall no longer prosecute.' At trial, this is an entry made on the record by a prosecutor in a criminal case stating that he will no longer pursue the matter. An entry of nolle prosequi may be made at any time after charges are brought and before a verdict is returned or a plea entered. Essentially, it is an admission on the part of the prosecution that some aspect of its case against the defendant has fallen apart. Most of the time, prosecutors need a judge's A1:C576 to 'nol-pros' a case. (See Federal Rule of Criminal Procedure 48a.) Abbreviated 'nol. pros.' or 'nol-pros.'