Arson is the crime of willfully and maliciously setting fire to or charring property. Though the act typically involves buildings, the term arson can also refer to the intentional burning of other things, such as motor vehicles, watercraft, or forests. The crime is typically classified as a felony, with instances involving a greater degree of risk to human life or property carrying a stricter penalty. A common motive for arson is to commit insurance fraud. In such cases, a person destroys their own property by burning it and then lies about the cause in order to collect against their insurance policy. A person who commits arson is called an arsonist. Arsonists normally use an accelerant (such as gasoline or kerosene) to ignite, propel and directionalize fires, and the detection and identification of ignitable liquid residues (ILRs) is an important part of fire investigations. Pyromania is an impulse control disorder characterized by the pathological setting of fires. Most acts of arson are not committed by pyromaniacs. The term derives from Law French arsoun (late 13th century), from Old French arsion, from Late Latin arsionem 'a burning,' from the verb ardere, 'to burn.' Historically, the common law crime of arson had four elements: Many U.S. state legal systems and the legal systems of several other countries divide arson into degrees, depending sometimes on the value of the property but more commonly on its use and whether the crime was committed in the day or night. Many statutes vary the degree of the crime according to the criminal intent of the accused. Some US states use other degrees of arson, such as 'fourth' and 'fifth' degree, while some states don't categorize arson by any degree. For example, in the state of Tennessee, arson is categorized as 'arson' and 'aggravated arson'. In the United States, the common law elements of arson are often varied in different jurisdictions. For example, the element of 'dwelling' is no longer required in most states, and arson occurs by the burning of any real property without consent or with unlawful intent. Arson is prosecuted with attention to degree of severity in the alleged offense. First degree arson generally occurs when people are harmed or killed in the course of the fire, while second degree arson occurs when significant destruction of property occurs. While usually a felony, arson may also be prosecuted as a misdemeanor, 'criminal mischief', or 'destruction of property.' Burglary also occurs, if the arson involved a 'breaking and entering'. A person may be sentenced to death if arson occurred as a method of homicide, as was the case in California of Raymond Lee Oyler and in Texas of Cameron Todd Willingham.