Gregory Brock says he was driving home with his two daughters when a Nassau County, Florida, sheriff's car cut him off. He called 911 to complain. Shortly after that, he says, that car stopped ahead of his and Adam Ardizzoni, a patrol officer, stepped out with his hand on his gun commanded him to stop. Brock says Ardizzoni told him he wasn't going to let him follow him home, and when he tried to explain he was going home, too, Ardizzoni told him he knew about his 911 call. Other deputies arrived and calmed the situation. A sheriff's office spokesperson says they are investigating Brock's complaint.