Simplify the following text for a Grade 9 native English-speaking person.
Original: Daniel Faulkner ( 1955 -- 1981 ) was a Philadelphia police officer who was murdered on December 9 , 1981 , a murder that Mumia Abu-Jamal was convicted of , but which many people think Mumia did not do .
Simplified: Daniel J. Faulkner ( December 21 , 1955 -- December 9 , 1981 ) was a police officer in the American city of Philadelphia who was shot and killed in the line of duty . Mumia Abu-Jamal was convicted of first-degree murder for the shooting and sentenced to death .