A masked man allegedly killed his college roommate with an AK-47 assault rifle in a dispute over counterfeit money on Staten Island, authorities said yesterday.

Armond Skrine, 34, of Queens, went to the Concord home of his former pal from the University of Waterbury in Connecticut, David Williams, 30, and blasted him at 11:50 a.m., Thursday, police said.

Cops arrived and arrested the alleged shooter.