developing police techniques:
-used evidence of post mortems like when a doctor suggested the cut marks on a victim indicated the ripper was left handed and had dissection experience
-this meant thr police could narrow down their search by looking at slaughter houses or hospitals
-the police followed up leads from articles by investigative journalists
-they followed up clues in the victims possession
-they visited lunatic asylums
-followed up coroners reports
-interveiwed key witnesses like Elizabeth Long who claimed to have seen Annie Chapman taking to a man minutes before she was found dead
-they set up soup kitchens to encourage poor people to come forward
-conducted house to house searches as criticism mounted and distributed 80000 handballs
-had almost no scientific forensic techniques