What Should You Do If You've Been Wrongfully Arrested? In the US, a "false arrest" requires that a LEO KNOWINGLY arrests a person against whom they do not have probable cause.The main difference between the two is that false arrest requires an arrest, but, false imprisonment only requires unlawful detention. In the first unnumbered paragraph, use whichever phrase, "false imprisonment" or. "false arrest," is more appropriate. 3. The plaintiff's claim in a warrantless false arrest lawsuit arose from a sheriff s deputy s visit to her house to check on the welfare of her daughter. The defendant filled out an incident report about the assault but did not assist in applying for the arrest warrant. Settlement for victim of false arrest and false imprisonment. Arresting the wrong person. 34. Ask them to fill out and sign a declaration.