Mumia Abu - Jamal 's case has become an international cause . He has filed appeals before the U.S. Supreme Court . Racism responsible for his conviction , death sentence , he says . Abu - Jamal convicted in 1981 murder of a police officer .
Mumia Abu-Jamal 's case has become an international cause . He has two appeals before the U.S. Supreme Court . Racism responsible for his conviction , death sentence , appeal says . Abu-Jamal convicted in 1981 killing of Philadelphia police officer .