Sorry, not going to get drawn into this.
As you say: "gangsters, murderers and political activists" and therefore well documented. A quick google search will start off your reseach, for a clearer picture of the overall civil rights movement which also links to the development of black music I can recommend the book "A Change is Gonna Come. Music, Race & The Soul of America " by Craig Werner. There are of course many other writings on this period of American history.
It is a complex and emotive subject and, as I said, the cause itself (although not the means) was justified. Never, in my opinion, was the somewhat over used cliche "One man's terrorist is another man's freedom fighter" more appropriate. It is this distinction which unfortunately became too blurred to lend historical credibility.
John.