In Illinois tonight(Waukegan) to be exact adapted this thing called 287 G. It will allow police to deport Illegal immgrants for crimes of death.
My first question is what does 287 G stand for? FBI, Federal bureau of Investion.
There was a massive group of people who attended the town hall meeting to see if it would pass or not.
Well it did.
Do you think this is a good thing?
Do you think the police would abuse their juristriction?

287(g) is a section of the Immigration and Nationality Act. Here is the link:

Immigration and Nationality Act... choose ACT 287.

I'll have to read more in order to answer your other questions.

The way I read this, the Attorney General can authorise States, "or any Political subdivision of States" with Federal powers delineated in the Act. i.e. the local township Sherriff will be able to act with the full powers and authority of the Federal Government on matters of immigration provided the township has entered into a written agreement with the USAG.

I haven't read the whole Act, so I don't know what those powers might be. But I bet the township won't be stumping up the cash to train their Sherriff on how to exercise these powers responsibly, and I doubt the Federal government will want to either. So I reckon it's a move to be seen to be doing something on immigration more than a move that will actually help to solve the problem - that would require fixing whatever it is in the source countries that makes the natives want to migrate in the first place.