(Portland, OR)  --  A police oversight group is urging the Portland City Council install a gunshot detection system.  The Focused Intervention Team Community Oversight Group has approved a proposal to Mayor Ted Wheeler to use ShotSpotter to help police respond to gun violence much faster.  The same system is used in several cities across the country.  However, the Chicago Inspector General found that 90-percent of the time officers could find no evidence of a shooting, even after they received an alert.