The 1st District Appellate Court last week criticized Cook County prosecutors for introducing to jurors a picture of a poorly altered photo making a defendant in a murder trial look as if he were wearing a ski mask.In the June 6 opinion, the panel ordered a new trial for the defendant, finding the photo evidence was prejudicial.The prosecution’s case hinged on one eyewitness’ identification of defendant Keith Middleton in a black half-ski mask, the panel found. There was no physical evidence connecting …