A Florida man has pleaded guilty in connection with the carjacking and kidnapping of a Connecticut couple, in what authorities call a failed ransom plot that may have been linked to a $240 million cryptocurrency heist. Michael Rivas was one of six men arrested after the series of events in Danbury on Aug. 25. He has plead guilty Thursday to kidnapping and conspiracy in federal court in Hartford and is set to be sentenced in May. The couple were assaulted but survived the ordeal. Danbury police say the FBI was investigating whether the couple's son was involved in a Bitcoin theft a week before the kidnapping.