How long can you legally detain someone?

In the United States, law enforcement can legally detain someone for a reasonable amount of time if they have a reasonable suspicion that the person has committed a crime or is about to commit a crime. This detention is typically limited to a few hours, but can vary depending on the circumstances. If there is probable cause to arrest the person, they can be held for a longer period of time. It is important to note that the exact duration of a legal detention can vary based on the specific laws and regulations of each jurisdiction.