I think it’s a good question and I’ve wondered about it myself. For example, there was the case of the guy in NYC who was strangled to death a month or so ago and that of course got some national attention, but it didn’t cause anywhere near the reaction (and riots, looting etc.) that Ferguson and the Trayvon case did. Why? I think it’s an open question and I don’t know the answer, but it occurs to me that if I were a reporter looking for a good story I’d be doing some investigating into all the out-of-state agitators, for a start.
There is something about these two cases getting the level of attention, including the White House’s attention and comment, that so many similar ones do not.
In the 25 years that I worked for a fire department in a city known for its crime problems I went to several people who died as a result of police actions and sometimes incompetence. There was no malice in any of the situations... the police didn't mean to kill any of them.
A lot of people who are high on drugs or drunk or both overexert their generally overweight out of shape bodies and have some type of cardiac event. Another common problem is the choke hold; the police cut off the blood to someones brain who is struggling with them for a little too long and they don't come back. Tasers kill more people than is generally acknowledged.
The other big one... is the police handcuff some big fat guy whose arms will barely go around his back, and then they leave him lying on his face and a few minutes later discover that he has suffocated.
Every one of the dead people related to police activity that we tried bring back was struggling and causing a lot of trouble for the police before their untimely demise. I personally have had difficulty holding down 100 pound women with six other guys. They scream, kick, punch, bite, spit and seem to have super human strength... it is absolutely amazing. No one who hasn't struggled with a crazy person has a clue how difficult it can be to restrain a psycho without hurting them or getting hurt yourself.
Last Christmas we responded to a drunk woman who was fighting with her neighbors. We were having difficulty calming her down so I called on the radio for police backup. I got a radio call back a few minutes later and the dispatcher said the police wanted to know why we needed them. I was just starting to think we had the situation under control, but as I started to fumble with my radio I took my eyes off her for just a second. She took the opportunity to punch me in the eye.
By the time the police arrived we had her calmed down and the police again wanted to know why we asked for them. My eye was starting swell a little. I didn't care about having her arrested for that, but I told them I thought we would probably be back if we just turned her loose. So a police officer started politely asking her questions. It looked like maybe we were just going to leave her when all of a sudden she went berserk and attacked the police officer and bit him on the arm hard enough to break his skin. Needless to say she was difficult to restrain but she did live through the ordeal.