The crime of assault varies from state to state (and under federal law), but is generally defined as intentionally putting another person in reasonable apprehension or fear of an imminent (immediate) harmful or offensive contact. The crime of assault may be committed even if there is no physical contact, as the criminal physical contact constitutes the separate crime of battery.

The crime of assault with a deadly weapon (also known as aggravated assault) occurs when someone uses a deadly weapon (gun, knife, club, tire iron, brass knuckles, etc.) during an assault.

In Maryland, assault is codified under Maryland Criminal Law Code Ann. § 3-201 et seq. The law defines assault as the crime of intentionally causing or attempting to cause serious physical injury to another, the intentional placing of another in reasonable fear of imminent bodily harm, or actually causing offensive physical contact. Assault in Maryland is categorized into two degrees. First-degree assault, which is a felony, involves the use of a firearm or intent to cause serious physical injury and carries a penalty of up to 25 years in prison. Second-degree assault, which can be a misdemeanor or a felony depending on the circumstances, includes all other types of assault and carries a penalty of up to 10 years in prison and/or a fine of up to $2,500. Assault with a deadly weapon would typically be charged as first-degree assault due to the use of a weapon capable of causing serious injury or death. Maryland law does not require physical contact for an assault charge; the act of placing another in fear of imminent harm is sufficient.