Draco doesn't seem convinced and Hermione has to hand it to him that he isn't one to be easily placated. The Ministry does want to catch the Ripper, it's bad press if nothing else, but not many of them are losing sleep over the dead Death Eaters. Of more concern are the half dozen dead muggle criminals that turned up in an empty field outside Kent the day after Malfoy was found. They had clearly been used to practice Dark magics on, or to power something, and there's a plethora of theories regarding that fact.