Roy Juvenile Law Lawyer, Montana

One of the most sacred principles in the American criminal justice system, holding that a defendant is innocent until proven guilty. In other words, the prosecution must prove, beyond a reasonable doubt, each element of the crime charged.

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 way the defendant can get out of jail, without paying bail, by promising to appear in court when next required to be there. Sometimes called 'personal recognizance.' Only those with strong ties to the community, such as a steady job, local family and no history of failing to appear in court, are good candidates for 'OR' release. If the charge is very serious, however, OR may not be an option.

A formal investigation -- governed by court rules -- that is conducted before trial. Discovery allows one party to question other parties, and sometimes witnesses. It also allows one party to force the others to produce requested documents or other physical evidence. The most common types of discovery are interrogatories, consisting of written questions the other party must answer under penalty of perjury, and depositions, which involve an in-person session at which one party to a lawsuit has the opportunity to ask oral questions of the other party or her witnesses under oath while a written transcript is made by a court reporter. Other types of pretrial discovery consist of written requests to produce documents and requests for admissions, by which one party asks the other to admit or deny key facts in the case. One major purpose of discovery is to assess the strength or weakness of an opponent's case, with the idea of opening settlement talks. Another is to gather information to use at trial. Discovery is also present in criminal cases, in which by law the prosecutor must turn over to the defense any witness statements and any evidence that might tend to exonerate the defendant. Depending on the rules of the court, the defendant may also be obliged to share evidence with the prosecutor.

A signed statement, sworn to be true by the signer, that will make the signer guilty of the crime of perjury if the statement is shown to be materially false -- that is, the lie is relevant and significant to the case.

A request submitted to the court before trial in an attempt to exclude evidence from the proceedings. A motion in limine is usually made by a party when simply the mention of the evidence would prejudice the jury against that party, even if the judge later instructed the jury to disregard the evidence. For example, if a defendant in a criminal trial were questioned and confessed to the crime without having been read his Miranda rights, his lawyer would file a motion in limine to keep evidence of the confession out of the trial.

The crime of breaking into and entering a building with the intention to commit a felony. The breaking and entering need not be by force, and the felony need not be theft. For instance, someone would be guilty of burglary if he entered a house through an unlocked door in order to commit a murder.