[Diogenesis]

"Extremly creepy. I wonder what they're up to?"

They want to murder Americans.
They want to obtain radiopharmaceuticals and radioisotopes.
They want the easy entry (and exit) ports to the hospitals for the next wave.

SOLUTION: Catch. Interrogate. Execute. Repeat.

[livius]

They want to obtain radiopharmaceuticals and radioisotopes.

I thought that, too. And your solution is the only one.