In many states across the country, criminal homicides go unsolved.  “The analysis of 52,000 criminal homicides goes beyond what is known nationally about the unsolved cases, revealing block by block where police fail to catch killers.  Detectives said they cannot solve homicides without community cooperation, which makes it almost impossible to close cases in areas where residents already distrust police. As a result, distrust deepens and killers remain on the street with no deterrent.”