Los Angeles (CNN) -- Rodney King's death in June was the result of accidental drowning, although alcohol, cocaine, marijuana and PCP found in his system were contributing factors, authorities said Thursday.

King, whose beating by Los Angeles police in 1991 was caught on camera and sparked riots after the acquittal of the four officers involved, was found dead in the swimming pool at his Rialto, California, home on June 17, authorities and his fiancee said. He was 47.