The case of infamous skyjacker DB Cooper may never be officially solved, but 40 years after the brazen event, the FBI is preparing to close the case anyway, reports the Daily Mail. The woman who stepped forward earlier this year, claiming the notorious Cooper was her late uncle, says that the FBI came to her home to gather more of Dan Cooper's possessions for DNA analysis, after previous attempts to match his DNA failed. She says that the FBI believes her uncle was actually the skyjacker, but even if they can't solve the case conclusively, they will be closing the file soon. The feds aren't talking, but they have called the niece a "credible witness," notes Northwest Cable News. (More DB Cooper stories.)