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 New York, assault is defined under the New York Penal Law Section 120.00 as intentionally causing physical injury to another person, recklessly causing physical injury, or negligently causing injury with a deadly weapon or dangerous instrument. The definition of assault in New York does require physical injury to another person, which distinguishes it from the broader definition that includes putting someone in fear of imminent harm. Assault on a police officer or peace officer is indeed a more serious offense in New York. According to Section 120.08 of the New York Penal Law, assaulting a police officer, peace officer, or an officer of the fire department is classified as Assault in the Second Degree, which is a felony. This law applies when the officer is performing official duties and the assailant intends to prevent them from performing a lawful duty or to cause serious physical injury.