If you run a business that is open to the public, one of your main concerns may be shoplifting, which costs retailers millions of dollars in lost revenue every year.
While detaining a suspected shoplifter can open you up to legal liability, you are not without recourse.
Your actions may actually be covered by the shopkeeper's privilege.
Generally speaking, when a person is wrongfully detained by a private individual, that individual may be liable for the tort of false imprisonment.
However, many states, either via statute or common law, recognize an exception, which is commonly known as the "shopkeeper's privilege."
If you suspect that a patron has shoplifted or is attempting to shoplift, the privilege will protect you from legal liability for false imprisonment if:
Probable cause in this manner requires specific evidence that would lead a reasonable person to believe that shoplifting has occurred or is attempted. A suspicion alone will not suffice.
As for a reasonable length of time, the shopkeeper's privilege only permits you to detain a suspected shoplifter for a short period. You can usually detain a person until police arrive or as long as reasonably necessary to check for concealed property.
With respect to how you detain a person, the key is to use as little force as possible. Excessive force or coercion will almost always open you up to liability.