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 Oregon, assault is categorized into different degrees, with Assault in the Fourth Degree being the least serious and Assault in the First Degree being the most serious. Assault in Oregon is defined under ORS 163.160-163.208. The basic definition aligns with the general concept of assault as intentionally causing physical injury to another, placing another in fear of imminent serious physical injury, or causing physical contact that is offensive or provocative. Assault can be elevated to a more serious charge if it involves the use of a weapon, results in serious physical injury, or is committed against a vulnerable victim, such as a child or an elderly person. Assaulting a public safety officer, such as a police officer or peace officer, while they are performing their official duties is indeed considered a more serious offense in Oregon and can lead to felony charges, specifically under ORS 163.208, which covers Assaulting a Public Safety Officer. The exact classification and penalties for assault offenses vary based on the circumstances of the crime, the degree of injury caused, and the defendant's criminal history.