missing teens? >> the rpnc have opened their investigation. the trail has gone cold in turkey. they believe they had left to go join isis but they have no idea where they ended up. what's interesting here is they were alerted to all of this from families. families increasingly separate seeing their children were being radicalized radicalized. some of them knowing they might believe the country. canada started trying to revoke the passports of those who they think might join isis. in this case that wasn't done. families are desperate to know more. >> paula, thank you very much. we're learning more about the man believed to be jihadi john. we now know his name.