Harvard has done a recent study that allows people to measure their subconscious prejudices through an online test. You can take it on a variety of issues (race, age, weight, sex, etc.) and it does a good job of showing how our minds work and associate positive feelings with some characteristics, and negative feelings with others. It points out that much of our prejudices are subconscious, and that we unable or unwilling to admit such feelings and prejudices. Here is the link.
https://implicit.harvard.edu/implicit/takeatest.html
I'm posting this here because after I took a couple of these tests I wondered about D. Wilson and some of his possible prejudices. Would the situation have gone down differently if Michael Brown was White? The short answer is that it probably would have changed the outcome to some extent. To what extent, and how much fault we can place on people due to their subconscious attitudes towards others (prejudices that we all have, mind you) is a difficult question to answer. Take the test and I bet you will be surprised at some biases and prejudices that you didn't know you had.