After shooting his son during a confrontation at home, Timothy Davis told responding officers he had acted in self-defense and later sued over his arrest and the search of his house. The Eleventh Circuit held that probable cause is judged from the facts known when officers acted, not from the later acquittal or from an obligation to eliminate every innocent explanation; the shooting, injuries, and circumstances supplied probable cause. It also held that the district court correctly followed the earlier mandate in refusing a custom-and-practice jury instruction, and affirmed the judgment for the City.