The idea that Freddie did this to himself is pretty conveeeeeenient, as Church Lady used to say.
I doubt that the cops wanted to kill him, but he was in custody, and now he's dead, so they are responsible for his being dead.
I am sure they will wriggle out of actual jail time. I will be surprised if even the cop in South Carolina ends up in jail. The strategy will be to delay, delay, delay, then obfuscate, and perhaps we will see a verdict in 2018.
The cops were not to blame, of course, as CU4 says, you have to be polite to cops even if their actions will wreck your entire life. They are like wolves or grizzly bears. One false move and you are lunch.