SACRAMENTO, Calif. — A man who was shot seven times by immigration agents in Patterson and then charged with using his car as a deadly weapon pleaded not guilty in Sacramento federal court Monday. Carlos Ivan Mendoza Hernandez appeared in court in a wheelchair, with a foam block supporting his wounded arm. In a sign, perhaps, of the significance his case had taken on, and the attention it had drawn, he was represented personally by federal public defender Heather Williams , the top lawyer in an office of 82 attorneys tasked with representing those who cannot afford to hire outside counsel for criminal cases in federal court. The hearing was Mendoza Hernandez’s first appearance before U.S. District Judge Dale Drozd since a federal grand jury indicted him in the case last week. Drozd read the three charges against Mendoza Hernandez — two counts of assaulting a federal officer and one count of destruction of government property.…