I knew that sooner or later someone was going to injured or killed by the police or national guard and would become the 'four dead in Ohio' type martyr of the 99%/OWS movement. That he was a former Marine with two tours in Iraq under his belt gives this living-martyr some traction with a wider audience.
The killing of those four students in Ohio focused the attention of people who had previously not supported or opposed the anti-war movement and many decided they supported the movement. It was a turning point in the anti-war movement and got politicians on both sides to really work toward ending the Vietnam War because it became the hot-button issue on a large portion of the electorate's mind and they saw their re-election chance's depended on being seen as trying to end the war.
Martyrs (living or dead) galvanized groups into an 'us versus them' mentality. Having someone get seriously injured or killed in a protest gives everyone a sense of having skin in the game. The more force that is applied to the protesters, the stronger this movement will become.
I know the national guard has not been used yet on the OWS/99% movement, but since they can be called up by governors, I don't believe it is too far-fetched to believe it could occur at some point in a state with a very conservative governor.