MEXICO CITY – A Mexican teen allegedly shot and killed by a U.S. Border Patrol agent had been detained in the United States 11 times for people smuggling, a Border Patrol spokesman said Wednesday. The shooting of Guillermo Martinez has intensified an already white-hot international debate about illegal immigration, and prompted Mexico to open a criminal investigation and send a diplomatic note to Washington. Opposition lawmakers have accused President Vicente Fox's government of not expressing sufficient outrage, however, and have vowed to consider a nonbinding resolution branding the 18-year-old an innocent victim and demanding that his shooting be punished.But Raul...