malpractice - A lawsuit brought against a professional person, such as a doctor, lawyer or engineer, for injury or loss caused by the defendant's negligence in providing professional services.  

mandamus - A writ by which a court commands the performance of a particular act.  

manslaughter - A person recklessly causes the death of another, or acting under extreme emotional disturbance, causes the death of another, or acting under circumstances when a person reasonably believes the circumstances provide a legal justification or excuse for his conduct constitutes manslaughter.  

material evidence - Evidence which is relevant to the issues in a case.  

mens rea - Literally, "guilty mind." The intent required to commit the crime. One of the two basic requirements, along with the guilty act (actus reus) which constitute a crime.  

Miranda rule - The rule, pronounced in Miranda v. Arizona, that confessions are inadmissible in a criminal prosecution if the police do not advise the suspect in custody of certain rights before questioning. The rights include:  

• a. The right to remain silent and to refuse to answer any questions;  
• b. The right to know that anything the suspect says can and will be used against the suspect in a court of law;  
• c. The right to consult with an attorney and to have an attorney present during questioning;  
• d. The right to have counsel appointed at public expense, prior to any questioning if the suspect cannot afford counsel.  

misdemeanor - A minor offense, lower than a felony, which is punishable by a county jail term of up to one year and/or a fine, but not prison. Misdemeanors are classified into three categories: Class A, B, and C.  

mistrial - A trial which is void because of some error.