One should keep in mind that the “civil” tort (a wrongful act) of “FALSE IMPRISONMENT” is much broader than the act involved in a “false arrest” under the criminal law.   While a “false arrest” committed by a police officer will fall under the civil concept of “false imprisonment”, there are any number of other situations, not necessarily involving police or official personnel, that will also be encompassed by “false imprisonment.”

Any time a perpetrator intentionally confines the victim to a specific area, and does it against the victim’s will, that will constitute a “false imprisonment.”

One of the most frequent instances of “false imprisonment” by non-police personnel involves retail establishment security personnel.   Someone thought to have shoplifted an item is detained, only to have store personnel find out a mistake was made.
A landlord, annoyed that a tenant has not paid his rent, locks the tenant in his tenth floor apartment.  This may well constitute “false imprisonment.”   Locking the tenant out of the apartment would not.

The yardstick is determined by the mental state of the victim.  If the perpetrator tells a person they are locked into a room, and the victim has grounds to believe it, even though the room is in fact unlocked, a “false imprisonment” has occurred.   Alternatively, if the victim is asleep when the perpetrator locks the room, and the perpetrator then unlocks the room before the victim awakens, the is no “false imprisonment.”.

As in all cases that are considered potential lawsuits, the issue of the amount of injury sustained by the victim becomes important to consider.