Fundamentally, the only authority the state can muster stems from fear and force. This is an example of both, as students who are sitting on the sidewalk at a UC Davis campus are pepper sprayed for not moving.
After the first officer (UC Davis Campus Police Lt. John Pike) begins, other officers begin threatening the surrounding crowd to allow the pepper spraying to continue. When the initiating officer empties his canister of spray, he motions and a second officer comes up to finish the job. Which he does.
This is not the deviant work of a single officer, but an large and powerful body of police working in cohesion to achieve the desired outcome, which was to displace protesters who harmed no one and caused no destruction. The means to do so is the raw use of force, which is the last resort of state authority.
And for everyone ever thrust into a conversation involving the lies that say a baby is a mass of unliving tissue, this extraordinary TED talk from December 2010 by Alexander Tsiaras, a mathetician / artist, author of The Architecture and Design of Man and Woman: The Marvel of the Human Body, Revealed. This is titled Conception to Birth, Visualized. (Warning, graphic in the Anatomy textbook sort of way)