[ConservingFreedom]

Has Ben Carson made similar statements condemning "knockout game", other acts of black-on-white violence, and black-on-white crime in general?

Yes: "The epidemic of black-on-black violent crime indicates that there has been a significant deterioration of values in the black community. Not only are the lives of their fellow blacks and others being devalued by street thugs, but the lives of unborn babies are being destroyed in disproportionate numbers in the black community." - http://www.washingtontimes.com/news/2013/aug/28/i-have-a-dream-50-years-later

[PapaBear3625]

"Has Ben Carson made similar statements condemning 'knockout game', other acts of black-on-white violence, and black-on-white crime in general?"

Yes: "The epidemic of black-on-black violent crime indicates that there has been a significant deterioration of values in the black community.

Not an answer to the question. Your quote has Carson decrying black-on-black violence, I specifically asked about black-on-white violence.