I don’t believe it. If it is true then it is just like saying that a Saudi can kill and main dozens of Americans and the US government will do nothing. That is insane, there must be some kind of mistake here. I refuse to believe it.
It doesn’t sound like a mistake to me. What the government is doing sounds entirely reasonable.
The authorities searched his place, and went over everything about him with a “fine toothed comb”. And while they didn’t find any connection to the bombing - they did find out he’s a national security risk. Hence, they are deporting him.
That’s what you do to people who you realize are national security risks, but they haven’t done anything yet. You don’t allow them to stay in the country to be able to “do something”.