Webthese 10 unsolved cases were reopened because of true crime podcasts and their supporters. Webwith nearly a quarter of a million cold cases still unresolved in the u. s. , there are a number of reasons cold cases are reopened by law enforcement. In a study released by the. Webexploring cold cases that have remained unsolved for decades can be an intriguing journey into the deepest mysteries of the criminal world. Over the years, the.