Back then, Cincinnati cops weren't killing black guys, but Cincinnati fans were disgustingly racist. The statue honors the moment at Crosley Field when Reds fans were taunting and jeering Robinson and Reese came over and put his arm around him to shut him up.
Things are somewhat better now than then, but racist remarks at GABp are a regular occurrence, and now Cincinnati cops are killing black guys for not having drivers licenses. (Of course, Cincinnati isn't alone in this trend.) Sadly, this statue in Brooklyn was vandalized with racist slurs and swastikas a few years ago.