Burglary is generally the unlawful entry of a building or structure to commit a felony criminal offense (crime), theft, or assault. The definition of burglary varies from state to state (and in the federal system), and some states have different degrees of severity of the burglary offense—depending on the nature of the unlawful entry (type of building or structure), the intended purpose, and the illegal action taken by the defendant once inside the building or structure. In some states, breaking into an automobile, a coin-operated machine, or an ATM (automated teller machine) with the intent to commit a theft may also constitute the crime of burglary.

In New York, burglary is defined under the New York Penal Law Sections 140.20 to 140.30. The state categorizes burglary into three degrees, with first-degree burglary being the most serious. Burglary in the third degree (NY Penal Law § 140.20) involves unlawfully entering or remaining in a building with intent to commit a crime therein. Second-degree burglary (NY Penal Law § 140.25) includes the same elements but becomes more severe if the building is a dwelling, if the crime is committed at night, or if the perpetrator is armed, injures someone, or displays what appears to be a firearm. First-degree burglary (NY Penal Law § 140.30) is charged when the burglary of a dwelling occurs with the aggravating factors of the second degree and includes physical injury to a non-participant or the use of a dangerous weapon. Burglary in New York does not typically include the unlawful entry into vehicles or other structures not classified as buildings; however, separate statutes address similar crimes involving these types of property.