As Philadelphia police concentrate on lowering the city's homicide rate, a new study has found evidence of a predictable pattern for one type of shooting — those classified as “near-repeats.” “Our study found that once there is a shooting on a street corner, the risk of another shooting within a block of that location over the next two weeks increases by a third,” said Criminal Justice Professor Jerry Ratcliffe, who coauthored the study with his colleague in the Criminal Justice Department, Professor George Rengert.