"The crime of intentionally starting a fire in order to damage or destroy something, especially a building." (CD)
See also: https://dictionary.cambridge.org/us/dictionary/english/arson
The graph displays the other subjects mentioned on the same pages as the subject "Crime--Arson". If the same subject occurs on a page with "Crime--Arson" more than once, it appears closer to "Crime--Arson" on the graph, and is colored in a darker shade. The closer a subject is to the center, the more "related" the subjects are.