Final answer:
Social host liability is the type of crime committed when someone knowingly permits a person under 21 to consume alcohol in on-sale premises.
Step-by-step explanation:
The crime that is committed when someone knowingly permits a person under 21 to consume alcohol in on-sale premises is known as social host liability. This refers to the legal responsibility of an individual who provides alcohol to underage individuals, even if they themselves did not directly sell or serve the alcohol. Social host liability laws vary from state to state, but generally hold individuals accountable for providing alcohol to minors.
An example of social host liability is if a parent hosts a party at their home and allows underage guests to drink alcohol. They could be held legally responsible for any negative consequences that result from the underage drinking, such as accidents or injuries.
Note that on-sale premises refers to establishments where alcohol is sold and consumed on the premises, such as bars, restaurants, and clubs.