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. In many states assaulting a police officer or peace officer who is performing official duties (such as making a lawful arrest) is a more serious offense—sometimes a felony.

In Maryland, assault is codified under Maryland Criminal Law Code Ann. § 3-201 et seq. The state recognizes assault in several degrees, with first-degree assault being the most serious, involving intentional causing or attempting to cause serious physical injury to another, or committing an assault with a firearm. This is a felony that can lead to up to 25 years in prison. Second-degree assault includes less serious physical injuries and offensive physical contact, and it can be treated as a misdemeanor or a felony, depending on the circumstances, with penalties of up to 10 years in prison and/or a fine. Maryland law also recognizes that assaulting certain individuals, such as law enforcement officers, parole and probation agents, firefighters, and emergency medical personnel, among others, while they are performing their official duties, is a more serious offense. This can elevate a second-degree assault to a felony with increased penalties, including longer prison terms and higher fines. It's important to note that in Maryland, assault does not require physical contact; the act of putting someone in fear of imminent harm can constitute assault.