Spencer Juvenile Law Lawyer, Iowa

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).

Laws written by Congress and state legislators that make certain behavior illegal and punishable by fines and/or imprisonment. By contrast, civil laws are not punishable by imprisonment. In order to be found guilty of a criminal law, the prosecution must show that the defendant intended to act as he did; in civil law, you may sometimes be responsible for your actions even though you did not intend the consequences. For example, civil law makes you financially responsible for a car accident you caused but didn't intend.

Listening to conversations or observing conduct which is meant to be private, typically by using devices that amplify sound or light, such as stethoscopes or binoculars. The term comes from the common law offense of listening to private conversations by crouching under the windows or eaves of a house. Nowadays, eavesdropping includes using electronic equipment to intercept telephone or other wire communications, or radio equipment to intercept broadcast communications. Generally, the term 'eavesdropping' is used when the activity is not legally authorized by a search warrant or court order; and the term 'surveillance' is used when the activity is permitted by law. Compare electronic surveillance.

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 negotiation between the defense and prosecution (and sometimes the judge) that settles a criminal case. The defendant typically pleads guilty to a lesser crime (or fewer charges) than originally charged, in exchange for a guaranteed sentence that is shorter than what the defendant could face if convicted at trial. The prosecution gets the certainty of a conviction and a known sentence; the defendant avoids the risk of a higher sentence; and the judge gets to move on to other cases.

A method of paying a lawyer for legal representation by which, instead of an hourly or per job fee, the lawyer receives a percentage of the money her client obtains after settling or winning the case. Often contingency fee agreements -- which are most commonly used in personal injury cases -- award the successful lawyer between 20% and 50% of the amount recovered. Lawyers representing defendants charged with crimes may not charge contingency fees. In most states, contingency fee agreements must be in writing.

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 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.