Criminal Law


  • Arson—Structural
  • Arson—Mobile
  • Arson—Other

Definition: Any willful or malicious burning or attempt to burn, with or without intent to defraud, a dwelling house, public building, motor vehicle or aircraft, personal property of another, etc.

Agencies must report as arson only fires determined through investigation to have been willfully or maliciously set. Attempts to burn are included in this offense, but fires of suspicious or unknown origins are not. Agencies must classify one offense for each distinct arson operation originating within the reporting jurisdiction. If an arson is perpetrated in one locale and spreads to another, the jurisdiction in which the fire originated must report it.


  • Single occupancy residential (houses, townhouses, duplexes, etc.)
  • Other residential (apartments, tenements, flats, hotels, motels, inns, dormitories, boarding houses, etc.)
  • Storage (barns, garages, warehouses, etc.)
  • Industrial/manufacturing
  • Other commercial (stores, restaurants, offices, etc.)
  • Community/public (churches, jails, schools, colleges, hospitals, etc.)
  • All other structure (out buildings, monuments, buildings under constructions, etc.)

In classifying the object of an arson as structural, reporting agencies must use the guidelines for defining structures set forth in the discussion of burglary in this handbook (page 28). A house trailer or mobile unit that is permanently fixed as an office, residence, or storehouse must be considered structural property.

Structures are further divided into two subcategories: residential and nonresidential. The UCR Program considers a residential structure to be any dwelling used for human habitation, including houses, townhouses, apartments, etc. In order to comply with the UCR definition of Arson—Single Occupancy Residential (8a) structures must meet all three of the following conditions:

  • Private dwellings, duplexes, townhouses, etc. each occupied by a single family group
  • Total sleeping accommodations for no more than 20 persons
  • No more than two rooms per unit rented to outsiders

The following scenario illustrates an incident known to law enforcement that reporting agencies must classify as Arson—Structural (8a-g):

  1. As the result of fire, several condominiums were destroyed or damaged. Investigation revealed an arsonist had ignited a fire in one condominium; however, the fire spread to several adjacent buildings, causing $400,000 total damage.

Residential property not meeting the above-listed criteria are classified as Other Residential (8b). For the purpose of reporting arson, temporary living quarters such as hotels, motels, inns, are included in the Other Residential category. The remaining structural subcategories address nonresidential property and are self-explanatory.


  • Motor vehicle (automobiles, trucks, buses, motorcycles, etc.)
  • Other mobile property (trailers, recreational vehicles, airplanes, boats, etc.)

Motor vehicles by UCR definition must be self-propelled and run on land surface and not on rails; for example, sport utility vehicles, automobiles, trucks, buses, motorcycles, motor scooters, all-terrain vehicles, and snowmobiles are classified as motor vehicles.

The following scenarios illustrate incidents known to law enforcement that reporting agencies must classify as Arson—Mobile (8h-i):

  1. Someone threw a firebomb at a parked vehicle; the device missed the car and burned harmlessly in the street.
  2. The owner of an airplane willfully burned it to collect the insurance money. The fire also damaged the plane's hangar; the estimated total loss was $450,000. The owner fled the area and could not be found.


The category Arson—Other (8j) subcategory encompasses arson of all property not classified as structural or mobile. Willful or malicious burnings of property such as crops, timber, fences, signs, and merchandise stored outside structures are included in this category.

The following scenario illustrates an incident known to law enforcement that reporting agencies must classify as Arson—Other (8j):

  1. A 16-year-old boy, whose motive was revenge, burned the timber belonging to a local rancher, causing $200,000 in damage. The police arrested the juvenile.

Cautions In Classifying Arson

Key to properly classifying arson is establishing the point of origin of a fire. If an individual willfully burns a vehicle parked adjacent to a home and the fire subsequently spreads to and destroys the home, the appropriate arson subcategory would be Mobile—Motor Vehicle (8h). In cases where the point of origin is undetermined or in instances of multiple points of origin, the agency must report the structural, mobile, or other category of property that suffered the greatest fire damage.

Incidents in which persons are killed as a direct result of arson are classified as both criminal homicides and arson. Similarly, the number of persons severely injured during an arson must be reported as aggravated assaults along with the arson.

NOTE: The Hierarchy Rule does not apply to the offense of arson. In cases in which an arson occurs in conjunction with another Part I crime, the agency must report both crimes, the arson and the additional Part I offense. For multiple offenses, one of which is arson, the reporting agency must report the arson and apply the Hierarchy Rule to the remaining Part I crimes to determine which one is the most serious and should also be reported.

The following scenarios illustrate incidents known to law enforcement that reporting agencies must classify both as Arson—Structural (8a-g) and the appropriate Part I offense:

  1. The police and fire investigators determined a fire was deliberately set in a single-family home valued at $165,000. Rescue workers assisted in helping the family escape; however, a child, aged 8, died at the scene from smoke inhalation. No arrests were made.

Explanation: Law enforcement must report arson and criminal homicide.

  1. Three individuals broke into a warehouse. While inside, they spray painted the walls. They located the night watchman and kicked him into unconsciousness. The watchman sustained several broken ribs. Prior to leaving, the vandals sloshed gasoline around the premises. The police arrived on the scene and apprehended two of the three suspects as they were attempt- ing to ignite the gasoline. Investigators estimated the damage at $4,000.

Explanation: Law enforcement must report arson and aggravated assault.

  1. A fire was reported at the local college dormitory. Ten students were killed as a direct result of the flames and asphyxiation. Two more students died from internal injuries received when they attempted to jump to safety. Six people were hospitalized with second- and third-degree burns. Final investigative reports of the incident revealed that tennis balls soaked in alcohol had been ignited against a dormitory room door as a prank.

Explanation: Law enforcement must report arson and criminal homicide.