Handout shows several bullet holes in the windshield of a police patrol car in Dallas, Texas

Several bullet holes are seen in the windshield of a police patrol car in Dallas, Texas, in this handout photo released by the Dallas Police Department on June 13, 2015. Shots were fired from what was described as an armored van in an attack on Dallas Police headquarters early on Saturday, police said, and an explosive device was found outside the building. REUTERS/Dallas Police Department/Handout via Reuters

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