The one from Brown U was probably s student visa; likely both of them.
The Arab kid who was a suspect at first but then all of a sudden cleared and sent back to Saudi Arabia had an extensive resume’ with AlQuida etc.. - may well have had something to do with it but has “diplomatic immunity”. The FBI probably got the “do not touch’ order from on high.
No, the Brown kid was born here. Dad is a CEO.
Foreigners like the area because they are easily accepted and can get “lost” among so many students. I use to go to Thayer Street in Providence, near Brown University and watch all the foreigners walking the street. Thayer was known to be the happening place...full of street restaurants and gift shops.