The shooting comes with gun violence fresh on the minds of many Americans, after a massacre on May 24 killed 19 school children and two teachers at an elementary school in Uvalde, Texas, and the May 14 attack that killed 10 people at a grocery store in Buffalo, New York.
Rooftop shooter kills 6 at July 4 parade in Highland Park
STORY: Police said they were searching for a white male about 18 to 20 years old and asked the public for tips and cellphone images and surveillance video to help find him.