DNA, fingerprint match: How FBI uncovered bomb suspect’s ID

WASHINGTON — In the hours before his arrest, as federal authorities zeroed in and secretly accumulated evidence, Cesar Sayoc was in his element: spinning classic and Top 40 hits in a nightclub where he’d found work as a DJ in the last two months.
As he entertained patrons from a dimly lit booth overlooking a stage of dancers at the Ultra Gentlemen’s Club, where Halloween decorations hung in anticipation of a costume party, he could not have known that investigators that very evening were capitalizing on his own mistakes to build a case against him.
He almost certainly had no idea that lab technicians had linked DNA on two pipe bomb packages he was accused of sending prominent Democrats to a sample of on file with Florida state authorities. Or that a fingerprint match had turned up on a separate mailing the authorities say he sent.