A Chicago police officer who shot an unarmed man in the back as he tried to escape capture by running up an escalator in a busy subway station has been charged with felony aggravated battery with a firearm and official misconduct, prosecutors said Thursday. The Cook County State’s Attorney’s office said in a news release that Melvina Bogard, 32, turned herself in to investigators on Thursday morning. At an afternoon bond hearing, Cook County Judge Susana Ortiz ordered that she be released on her written promise to appear …