U.S. Federal agents for years monitored one of the two gunmen shot dead after opening fire with assault rifles at a heavily guarded Texas exhibit of caricatures of the Prophet Mohammad. Two law enforcement officials, who asked not to be named, identified one of the dead shooters as Elton Simpson, under surveillance since 2006 and convicted in 2010 of lying to FBI agents over his desire to join violent jihad in Somalia. The second shooter was identified as Nadir Soofi, a roommate of Simpson, according to two sources close to the investigation. The shooting incident in the Dallas, Texas, suburb was an echo of past attacks or threats in other Western countries against art depicting the Prophet Mohammad. In January, gunmen killed 12 people in the Paris offices of French satirical magazine Charlie Hebdo in what it said was revenge for its cartoons.