There is many different theories about him, but from what I think, he is not dead.
First of all; why'd they bury him at sea?
Second: Why kill him right away? They could've brought him to court or something.
There is just more and more lies from the US government, they think we're so dumb we can't tell lies from the truth.
The government lies to us over and over, and the majority of the country take it as truth.
I've heard that the government will shut down the internet if we get too much educated in these kind of things.
Which I highly doubt.