Complex sentence: Joseph served time for his role in the murder of Sam Napier, circulation manager of'The Black Panther' as part of a series of retaliatory assassinations caused by a factional dispute within the Panthers.
Split into simpler sentences: Joseph served time for his role in the murder of Sam Napier. Napier was circulation manager of'The Black Panther', and was murdered as part of a series of retaliatory assassinations caused by a factional dispute within the Panthers.