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 Colorado, arson is classified as a serious criminal offense and is codified under state statutes. The severity of the charge and the associated penalties depend on the circumstances surrounding the act. Colorado law recognizes four degrees of arson. First-degree arson (CRS 18-4-102) is the most severe and is charged when a person knowingly sets fire to a building or occupied structure, potentially endangering human life; it is a class 3 felony. Second-degree arson (CRS 18-4-103) involves setting fire to property other than a building or occupied structure, and the severity of the charge can range from a class 2 misdemeanor to a class 4 felony, depending on the value of the damaged property. Third-degree arson (CRS 18-4-104) is charged when a person uses fire or explosives to commit insurance fraud, and it is a class 4 felony. Fourth-degree arson (CRS 18-4-105) applies when a person endangers another or their property by starting a fire or causing an explosion; it can be a class 2 misdemeanor or a class 4 felony, depending on whether there is a risk to life. Additionally, federal law prohibits arson in circumstances involving interstate or foreign commerce, which can lead to federal charges if the arson affects trade or commerce across state lines or national borders.