From my observation Binyamin Yisrael is correct. A black with both first and last arabic names is almost surely a muslim. First name only- can be "swahili" name, which is ridiculous since the African Americans originated from the bantu speaking west Africans rather than the arabized slave traders "swahilis" of east Africa.
One case I am not sure of is the Shakur clan of the black panthers/black liberation army including cop murderess Assati Shakur who escaped to Cuba and her famous relative, slain rapper Tupac Shakur.