The Rachel Maddow Show 09/19/16

Multitude of clues gives bombing investigators lots of work with

Rukmini Callimachi, a reporter for the New York Times who covers ISIS and al Qaeda, talks with Rachel Maddow about what leads ISIS to claim credit for attacks in the U.S. and what investigative routes are being explored in the Ahmad Khan Rahami case. ... more Duration: {{video.duration.momentjs}}