ORLANDO, Fla. (AP) — When Omar Mateen claimed to have explosives during the Pulse nightclub shooting rampage in June, two bomb-sniffing dogs got a “positive hit” on his vehicle outside the gay bar.While authorities investigated, many of the hundreds of first responders on the scene were ordered to back away from a perimeter that had been set up around the nightclub, according to a timeline of events obtained by The Associated Press through a public records request.Command centers were also relocated as a precaution. As it turns out, it was ammunition and weapons, not explosives in the car, according to dispatcher logs and the timeline.The timeline offers new insight into the police and firefighter response to the worst mass shooting in modern U.S. history, particularly the role that the bomb dogs played and how first-responders reacted to the dogs’ hit. The FBI is still investigating the massacre.