People run for cover at the Route 91 Harvest country music festival after apparent gun fire was heard on October 1, 2017 in Las Vegas, Nevada. (Photo by David Becker/Getty Images)
A person takes cover at the Route 91 Harvest country music festival after apparent gun fire was heard on October 1, 2017 in Las Vegas, Nevada. (Photo by David Becker/Getty Images)
A police helicoper circles the Mandalay Bay and Luxor hotels on October 1, 2017 in Las Vegas, Nevada. A gunman opened fire on a music festival in Las Vegas, killing at least 20 people. (Photo by David Becker/Getty Images)
Las Vegas Metropolitan Police officers run down Tropicana Ave. near Las Vegas Boulevard after a mass shooting at a country music festival nearby on October 2, 2017 in Las Vegas, Nevada. (Photo by Ethan Miller/Getty Images)
An injured person is tended to in the intersection of Tropicana Ave. and Las Vegas Boulevard after a mass shooting at a country music festival nearby on October 2, 2017 in Las Vegas, Nevada. (Photo by Ethan Miller/Getty Images)
People tend to the wounded outside the Route 91 Harvest Country music festival grounds after an apparent shooting on October 1, 2017 in Las Vegas, Nevada. (Photo by David Becker/Getty Images)
People run from the Route 91 Harvest country music festival after apparent gun fire was hear on October 1, 2017 in Las Vegas, Nevada.(Photo by David Becker/Getty Images)
People run from the Route 91 Harvest country music festival after gun fire was heard on October 1, 2017 in Las Vegas, Nevada. (Photo by David Becker/Getty Images)
An ambulance leaves the intersection of Las Vegas Boulevard and Tropicana Ave. after a mass shooting at a country music festival nearby on October 2, 2017 in Las Vegas, Nevada. (Photo by Ethan Miller/Getty Images)
A man lays on top of a woman as others flee the Route 91 Harvest country music festival grounds after a active shooter was reported on October 1, 2017 in Las Vegas, Nevada. (Photo by David Becker/Getty Images)
A Las Vegas Metropolitan Police officer stands in the intersection of Las Vegas Boulevard and Tropicana Ave. after a mass shooting at a country music festival nearby on October 2, 2017 in Las Vegas, Nevada. (Photo by Ethan Miller/Getty Images)
Police officers stand by as medical personnel tend to a person on Tropicana Ave. near Las Vegas Boulevard after a mass shooting at a country music festival nearby on October 2, 2017 in Las Vegas, Nevada . (Photo by Ethan Miller/Getty Images)