The man who was killed by police in Madison, Wisconsin, a shocking caught-on-camera shooting — sparking protests — was a violent ex-con with a lengthy record, including for assaulting cops, The Post can reveal. Corey Durrell Ruiz, 38, was identified by local officials and his family in social media posts. State Rep. Shelia Stubbs, a Democrat, said Ruiz “should still be alive.” Brandi Grayson, the head of the Madison-based black community advocacy group Urban Triage, decried the shooting as, “Another black man is dead on a Madison street.” Protesters have flooded the streets of Madison, Wisconsin, where the shooting happened...