Agent's shot kills rock thrower at border fence U.S. officers trying to arrest border crosser assaulted by rocks, spiked piece of wood June 22, 2011 San Ysidro, Ca. An illegal alien was shot and killed trying to enter the United States of America illegally by the U. S. Border Patrol. The BP agents said three men were coming through a hole in the border fence around 7:30 p.m Tuesday. Two of the illegal aliens ran back into Mexico through the hole in the fence. The agents were able to restrain the third man who violently resisted arrest. As the struggle ensued one of the other men leaned over the top of the fence and hurled large rocks and a piece of wood with nails sticking out of it at the agents, San Diego Police homicide Lt. Ernie Herbert said. The piece of wood hit one of them in the head, the lieutenant said. As the man began to throw another rock the other agent opened fire, hitting him once. He fell back into Mexico and died at the scene, Herbert said. A Border Patrol report is expected to be released today.