Knox Criminal Lawyer, Pennsylvania

An affirmative defense to a crime. Self-defense is the use of reasonable force to protect oneself from an aggressor. Self-defense shields a person from criminal liability for the harm inflicted on the aggressor. For example, a robbery victim who takes the robber's weapon and uses it against the robber during a struggle won't be liable for assault and battery since he can show that his action was reasonably necessary to protect himself from imminent harm.

The burden of proof that the prosecution must carry in a criminal trial to obtain a guilty verdict. Reasonable doubt is sometimes explained as being convinced 'to a moral certainty.' The jury must be convinced that the defendant committed each element of the crime before returning a guilty verdict.

The money posted by a 'bondsman' for a defendant who cannot afford his bail. The defendant pays a certain portion, usually 10%. If the defendant fails to appear for a court hearing, the judge can issue a warrant for his arrest and threaten to 'forfeit,' or keep, the money if the defendant doesn't appear soon. Usually, the bondsman will look for the defendant and bring him back, forcefully if necessary, in order to avoid losing the bail money.

The component parts of crimes. For example, 'Robbery' is defined as the taking and carrying away of property of another by force or fear with the intent to permanently deprive the owner of the property. Each of those four parts is an element that the prosecution must prove beyond a reasonable doubt.

Evidence that proves a fact by means of an inference. For example, from the evidence that a person was seen running away from the scene of a crime, a judge or jury may infer that the person committed the crime.

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.

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.

A document issued by a judge or magistrate that authorizes the police to arrest someone. Warrants are issued when law enforcement personnel present evidence to the judge or magistrate that convinces her that it is reasonably likely that a crime has taken place and that the person to be named in the warrant is criminally responsible for that crime.

A branch of the United States government with power derived directly from the U.S. Constitution. Federal courts decide cases involving the U.S. Constitution, federal law--for example, patents, federal taxes, labor law and federal crimes, such as robbing a federally chartered bank--and cases where the parties are from different states and are involved in a dispute for $75,000 or more.