Arson is the intentional burning of property—such as a building, car, boat, crops, or trees—with criminal or fraudulent intent. The criminal intent or motive behind arson is often insurance fraud—such as when the owner of property intentionally burns it and then files an insurance claim without disclosing the owner intentionally started the fire.

Arson is a felony offense under most state laws, but there are often different degrees of severity, depending on factors such as whether the fire results in physical injury or death. Arson is also a crime under federal law, which makes it illegal to use fire or an explosive to damage or destroy property used in interstate or foreign commerce, or in any activity affecting interstate or foreign commerce.

In Missouri, arson is considered a serious felony offense. The state statutes define different degrees of arson based on the circumstances of the crime. First-degree arson, under Missouri law, involves knowingly setting fire to a building or inhabitable structure when people are present or when the perpetrator should have known that people could be present, which could result in injury or death. This is the most severe form of arson and is treated as a Class B felony. Second-degree arson is when a person knowingly sets fire to a building or property to damage it, without the factors that elevate it to first-degree, and is classified as a Class D felony. Additionally, Missouri law recognizes a crime of 'knowingly burning or exploding,' which is a Class E felony, and 'reckless burning or exploding,' which is a Class A misdemeanor. The severity of the punishment can increase if the arson results in death or injury, or if it was done for fraudulent purposes, such as insurance fraud. Federal law also criminalizes arson, particularly when it involves property used in interstate or foreign commerce, or affects such commerce. The federal arson statute can impose severe penalties, including imprisonment, fines, or both.