In secretly-recorded phone calls, a Mount Vernon police officer said police let the man go for weeks because of an ongoing federal drug operation, despite the risk of bloodshed. Those calls are part of a trove of phone conversations recorded by a whistleblower cop in Mount Vernon, a small, majority Black city just north of the Bronx. Between 2017 and this year, the whistleblower recorded hours of phone calls he had with his fellow officers, gathering claims of police framing and assaulting innocent residents and working with favored drug dealers, as WNYC has previously reported.