Here are some statistics: http://webcache.googleusercontent.com/search?q=cache%3ADqQNf...
A couple key points: - More people in the US are struck each year by lightning than are killed by police. (373)
- Of the 1,491 persons that died from police use of force from 2009-2012: 915 (61.4%) were white males 481 (32.2%) were black males 48 (3.2%) were males of other races 28 (1.9%) were white females 15 (1.1%) were black females 4 (0.2%) were females of other races
- Of the 56,259 homicides from 2009-2012, 19,000 (33.8%) were killings of black males. Comparisons by types of homicides of black males: 481 (2.5%) were the result of police use of force 152 (0.8%) were the result of a negligent accident homicides (i.e., child playing with a gun) 648 (3.4%) were the result of a justifiable homicides by private citizens acting in self-defense 17,719 (93.3%) were criminal homicides (murders)
More blacks are killed in justifiable self-defense scenarios than are killed by police. And overwhelmingly more are killed in homicides, mainly by other blacks.
Also note: According to the US Department of Justice, blacks accounted for 52.5% of homicide offenders from 1980 to 2008, with whites 45.3% and "Other" 2.2%. The offending rate for blacks was almost 8 times higher than whites, and the victim rate 6 times higher. Most homicides were intraracial, with 84% of white victims killed by whites, and 93% of black victims killed by blacks. (Whites are being lumped in with Hispanics here.)
It's fairly clear that there isn't an epidemic of wide scale police violence against blacks. Instead, a few incidents have been blasted onto social media, and uncritical leftists have picked them up and ran with them. I see Black Lives Matter more as an expression of intergroup competition and aggression against traditionally white power structures. Other leftist groups take the same approach, e.g. with feminist fabrications about mass rapes on college campuses - college campuses are in fact among the safest places in the world, but feminists treat them as though they're some Mad Max-esque raping dystopia by claiming nonsense like 1 in 4 college girls get raped. They're mysteriously silent about places where real mass raping occurs, such as Africa and the Middle East.
I could go on, but suffice to say, I believe we're in a period of mass hallucination and hysteria, with entire movements justifying their existence on statistically nonsensical claims. This has happened many times throughout history, and it's leaned to both the right and left axes of the political spectrum. This time the wind just happens to be blowing to the left.