Carnival Cruise Teen death investigation

New documents suggest the FBI is investigating the step-sibling of a Florida high school cheerleader found dead on a cruise ship. Anna Kepner, a varsity cheerleader, was found dead on Nov. 7, according to authorities. The vessel returned to port in Miami a day later, and her remains were sent to the Miami-Dade County Medical Examiner's Office for an autopsy. Now we're learning Kepner's step-sibling is being investigated in relation to her death.