Navalny’s widow says lab tests prove he was poisoned

The widow of former Russian opposition figure Alexey Navalny, Yulia Navalnaya, has claimed in a video on social media that she has proof her husband was poisoned. Navalnaya claims to have smuggled biological material from where her husband had been held and that tests by two laboratories came to the same conclusion. The Kremlin says it is "unaware" of the accusations. CNN's Clare Sebastian reports.