Section 287(g) of the Immigration and Nationality Act allows the Department of Homeland Security to enter into assistance compacts with state and local governments in order to find, arrest and deport illegal immigrants. Both sides must agree on the terms of the program before it is implemented. The DHS provides 287(g) training for state and local law officers to ensure the sharing of best practice. Joint operations under this section allow the various agencies to enforce immigration law more effectively.
287(g) began with the 1996 amendments to the Immigration and Nationality Act passed by Congress. It is currently a volunteer program, though some would like it to be made mandatory.
One of 287(g)s successes is Mecklenburg county, North Carolina, whose 287(g) trained police force have caught over 1,000 illegal immigrant criminals who have committed a state crime.