Since Calderon took office in December 2006, more than 40,000 people have died in drug related violence. The president also struck out at the United States for failing to stop guns sold in the U.S. from reaching Mexican criminals, and urged the U.N. to take on the problem. Tests show that a majority of the automatic rifles in the hands of Mexican criminals were purchased in gun stores north of the border. "For what reason do criminals have access to AK47s, grenades and rocket launchers?" Calderon asked. "The U.N. has work to do on this."