Simplify the following text for a Grade 8 native English-speaking person.
Original: Chief Constable is the title given to the chief police officer of every territorial police force in the United Kingdom except for the City of London Police and the Metropolitan Police , as well as the chief officers of the British Transport Police , Ministry of Defense Police , Civil Nuclear Constabulary and Isle of Man Constabulary .
Simplified: A Chief Constable is the top police officer in a police force in the United Kingdom . Every police force in the United Kingdom has a Chief Constable except the City of London Police and the Metropolitan Police Service .