I doubt very seriously if the assassination of Malcolm X is being investigated, actively or otherwise. At least not by any law enforcement agency in any official capacity. The reason being, that Talmadge Hayer, Norman Butler, and Thomas Johnson were convicted of his murder in March of 1965. Hayer confessed to the crime but testified that Butler and Thomas were not present and had no part in X's murder. Nevertheless, they were all convicted and sentenced to life. As to the prevailing theory about his assassination, unfortunately, it seems that conspiracy theorists are leaning on opposite ends of the scale. One side seems to theorize that the assassination was masterminded by the Nation of Islam itself. This due to a conflict between X and NOI founder Elijah Muhammed. X's popularity was on the rise and there was talk of him breaking away from the NOI and heading his own organization. Thereby dividing the tide. The other side seems to theorize that X's assassination was the result of a government plot that also included the assassination of Dr. Martin Luther King, just over 3 years later. X's human rights visit to Africa and the Near East led him to being viewed as a "radical" and a "threat" to the US government and to both its domestic and foreign policies. This theory being supported by the fact that the FBI and the CIA both kept a file on X and MLK. It has also come to light that one of X's own bodyguards was actually an undercover agent for New York City's organized crime and anti-Communist unit. Some theorists however, have managed to meet on common ground and state that it was a conspiracy by both the US Gov't and the NOI. This being backed up by the fact that the treasurer of the NOI, James Ali, was an FBI informant. As you can see, many theories exist and I am afraid that we will never know the complete truth. Unfortunately, it would seem that those that are truly guilty of the assassination of Malcolm X, wound up using his most famous quote against him: "By any means necessary"~~Malcolm X Shabazz