Simplify the following text for a Grade 10 native English-speaking person.
Original: Harold Shipman ( 14 January 1946 â `` 13 January 2004 ) was a British general practitioner ( a type of doctor ) and serial killer .
Simplified: Harold Fredrick Shipman ( 14 January 1946 -- 13 January 2004 ) was a convicted English serial killer .