According to who? It's like meth vs alcohol. Alcohol kills vastly more people because there is much more of it around you. But meth is far, far, far more dangerous. It's just not as common. Same goes for this: cops kill more Americans than ISIS because they are everywhere while ISIS is 9000 miles away. Bees kill more Americans annually than ISIS. So what?
People assault cops way more than they do members of ISIS so of course the police will kill more of them. The lefts war against white people is well documented. Since all their other "wars" have fizzled out they have now moved on to this. The bottom line is that they need someone to hate and to pin their failures on so right now it's whites.