Care to help with a debate?

So there is a dispute over the quote that is posted all over the social sites: “I mourn the loss of thousands of precious lives, but I will not rejoice in the death of one, not even an enemy.”

Some are saying it was said by MLK or MLK Jr.

Others are saying it was actually penned by a 24 year old teacher named Jessica Dovey.

It is being said that Jessica Dovey posted her own quote from above, and right underneath it, she posted the following real quote from MLK Jr.: “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. ~ Dr. Martin Luther King Jr.”

Okay researchers: is it really a quote from MLK Jr.? Or did Jessica Dovey’s own words get mixed into the actual quote by eager posters on the social websites?