Stambaugh Juvenile Law Lawyer, Michigan

The mental component of criminal liability. To be guilty of most crimes, a defendant must have committed the criminal act (the actus reus) in a certain mental state (the mens rea). The mens rea of robbery, for example, is the intent to permanently deprive the owner of his property.

Testimony or other evidence that fails to meet state or federal court rules governing the types of evidence that can be presented to a judge or jury. The main reason why evidence is ruled inadmissible is because it falls into a category deemed so unreliable that a court should not consider it as part of a deciding a case --for example, hearsay evidence, or an expert's opinion that is not based on facts generally accepted in the field. Evidence will also be declared inadmissible if it suffers from some other defect--for example, as compared to its value, it will take too long to present or risks enflaming the jury, as might be the case with graphic pictures of a homicide victim. In addition, in criminal cases, evidence that is gathered using illegal methods is commonly ruled inadmissible. Because the rules of evidence are so complicated (and because contesting lawyers waste so much time arguing over them) there is a strong trend towards using mediation or arbitration to resolve civil disputes. In mediation and arbitration, virtually all evidence can be considered. See evidence, admissible evidence.

A decision by the jury to acquit a defendant who has violated a law that the jury believes is unjust or wrong. Jury nullification has always been an option for juries in England and the United States, although judges will prevent a defense lawyer from urging the jury to acquit on this basis. Nullification was evident during the Vietnam war (when selective service protesters were acquitted by juries opposed to the war) and currently appears in criminal cases when the jury disagrees with the punishment--for example, in 'three strikes' cases when the jury realizes that conviction of a relatively minor offense will result in lifetime imprisonment.

A type of behavior that is has been defined by the state, as deserving of punishment which usually includes imprisonment. Crimes and their punishments are defined by Congress and state legislatures.

A lawyer who is elected to represent a state government in criminal cases in a designated county or judicial district. A D.A.'s duties typically include reviewing police arrest reports, deciding whether to bring criminal charges against arrested people and prosecuting criminal cases in court. The D.A. may also supervise other attorneys, called Deputy District Attorneys or Assistant District Attorneys. In some states a District Attorney may be called a Prosecuting Attorney, County Attorney or State's Attorney. In the federal system, the equivalent to the D.A. is a United States Attorney. The country has many U.S. Attorneys, each appointed by the President, who supervise regional offices staffed with prosecutors called Assistant United States Attorneys.

A minor violation of the law that is punishable only by a fine--for example, a traffic or parking ticket. Not all vehicle-related violations are infractions, however--refusing to identify oneself when involved in an accident is a misdemeanor in some states.

A prosecution for murder in which the jury is also asked to decide if the defendant is guilty and, if he is, whether he should be put to death. When a prosecutor brings a capital case (also called a death penalty case), she must charge one or more 'special circumstances' that the jury must find to be true in order to sentence the defendant to death. Each state (and the federal government) has its own list of special circumstances, but common ones include multiple murders, use of a bomb or a finding that the murder was especially heinous, atrocious or cruel.

A peace officer for a particular geographic area -- most often a rural county -- who commonly has the power to serve legal papers, arrest lawbreakers and keep the peace. Depending on the state, a constable may be similar to a marshal or sheriff.