Its very likely that Russia was the foreign government who warned us about him in 2011.
This is looking like the Yorkshire Ripper, when the cops interviewed him 9 times and let him go and he killed more.
Did Obama’s justice dept under Holder not do what they are supposed to do? Are they not following up on radical Islamists because it is not PC? Easier to drone than question and these are the results. They were warned and let him go.
The best possible source. Being essentially in the same boat as the U.S. in terms of terrorist attacks, they are immune from the fear of reprisals.
I bet that Russia has no problems with "tourist" visas, or humanitarian ones being granted to chechens...