I refer you to the article by Ron Unz. All the facts you need to quote at your next dinner party where some twit speaks in favour of the sainted Trayvon Martin and that dreadful man, George Zimmerman.
Here is a sample paragraph:
One obvious reaction to these concerns was strong political support for a massive national crackdown on crime, and the prison incarceration of black men increased by almost 500% during the two decades after 1980. But even after such enormous rates of imprisonment, official FBI statistics indicate that blacks today are still over 600% as likely to commit homicide than non-blacks and their robbery rate is over 700% larger; these disparities seem just as high with respect to Hispanic or Asian immigrants as they are for whites. Thus, replacing a city’s blacks with immigrants would tend to lower local crime rates by as much as 90%, and during the 1990s American elites may have become increasingly aware of this important fact, together with the obvious implications for their quality of urban life and housing values.