I also found The Martin Luther King, Jr. Research and Education Institute, where you can find MLK's sermons, speeches, and papers.
Could the violence we see and experience outside of ourselves (the kind MLK seems to be speaking about below) be symbolic and reflective of an inner violence that we wage within and against ourselves?
THE WEAKNESS OF VIOLENCE
"The ultimate weakness of violence is that it is a descending spiral, begetting the very thing it seeks to destroy. Instead of diminishing evil, it multiplies it. Through violence you may murder the liar, but you cannot murder the lie, nor establish the truth. Through violence you may murder the hater, but you do not murder hate. In fact, violence merely increases hate. So it goes. Returning violence for violence multiplies violence, adding deeper darkness to a night already devoid of stars. Darkness cannot drive out darkness: only light can do that. Hate cannot drive out hate: only love can do that."