How Do We Find The Killers In Our Community?

You would think gun violence just happens out of nowhere, that someone lands a spaceship in our neighborhood, gets out and shoots people, then goes back up into space. Why are people afraid to speak out? We have cell phone videos that have exposed dirty cops that beat and shoot unarmed people, putting the heat on law enforcement to clean up its act, throw out the trash and get rid of those who have no business policing others. How about we use our technology to expose the rats and snakes among us in the community. If a Facebook page were created to post anonymously those who commit crimes, face, name, address, etc., would this help legitimate police capture those who commit crime? We can't stop crime until we remove fear and we can't remove fear until we create trust of police and we can't trust police until police remove corrupt cops from the ranks. But how about creating a social media network to expose wrongdoers? And what if cops still do nothing? Do we enact "street justice"? What do you think?