他要是做违法的事呢?要是没钱生活来敲诈我呢?警察会帮他来找我麻烦不?
-If he gets the B2 visa to enter US and the I-94 is 6 months, you need to provide him the living fee for 6 months if you are committed to support him travel financially when he applys for the B2 visa. If he stays in US illegally after that, you do not have any responsibilty on him. In US, everyone follows the law including the police on this kind of things.