Jack Mannion comes to the District of Columbia as the new Chief of Police. Chief Mannion believes in justice and has his elite team of law enforcers to help him keep justice in the nation's capital. He is very good friends with Ella Farmer, and when she passed away at the end of the third season, he took it very hard. Chief Mannion also hires his ex-wife Sherry Regan later in the series. Mannion also has two children.