article_snippet: Three days later, a Dallas detective found surveillance footage from a nearby elementary school showing four people coming from a Dallas apartment complex.
article_snippet: The black-and-white soundless surveillance video shows one person apparently carrying a rifle is seen running just ahead of a second person seemingly carrying a hand gun, Dallas police Officer Monica Cordova said.
article_snippet: Approximately 13 seconds later, another person comes into view and passes by the camera, followed by a fourth individual who is walking, Dallas police Officer Monica Cordova said.
article_snippet: Then all of them bolted.