Photo Gallery: Occupy Wall Street protestors: Oct. 27, 2011 1/20

Navy veteran Josh Shepherd, left, and Marine Corps veteran Matt Howard talk about their experience during ant-wall street protests where fellow veteran Scott Olsen was injured Thursday, Oct. 27, 2011 in Oakland, Calif. Oakland's police chief has pledged a vigorous investigation into a clash between police and Occupy Wall Street protesters that left an Iraq War veteran in critical condition with a fractured skull. (AP Photo/Marcio Jose Sanchez) ORG XMIT: CAMS101