If this thread refers to the stabbings and automobile collisions with pedestrians on the OSU campus the immigrant in question had been thoroughly vetted and granted "permanent residence" status by the United states Government under the leadership of The Obama. [One site which DonDiego perused stated that he had been granted "temporary permanent residence" status, but as DonDiego cannot determine what that could possibly mean he did not employ that term.]
Here is the plan for the immediate future as put forward by the soon-to-be-departed Obama:

Oh well, there's bound to be a bad egg or two in a basket that large. DonDiego supposes those lofty goals may decline somewhat.
DonDiego suggests maybe it's time to alter the goal of admitting ever-increasing poorly-vetted refugees from areas of the globe in which the citizens wish the destruction of the United States. Instead he suggests concentrating on admitting new immigrants based upon what they can add to the US society and economy, . . . instead of what the US citizens can provide to them.
Oh and vet them too, just in case ! Fr'instance, if their religion includes decapitation of non-believers it might be best to not admit them.
But then pro old DonDiego is old-fashioned that way.