A police officer runs along a sidewalk near a shooting near the Mandalay Bay resort and casino on the Las Vegas Strip. John Locher / AP Photo
People scramble for cover at the Route 91 Harvest country music festival after gunfire was heard on October 1, 2017 in Las Vegas, Nevada. David Becker / Getty Images
Festival goers run for their lives. David Becker / Getty Images
Las Vegas police stand guard along the streets near the concert. David Becker / Getty Images
A body is covered with a sheet in the intersection of Tropicana Avenue and Las Vegas Boulevard South after a mass shooting at a music festival on the Las Vegas Strip in Las Vegas. Steve Marcus / Las Vegas Sun / Reuters
Las Vegas Metro Police officer stands by at a staging area in the junction of Tropicana Avenue and Las Vegas Boulevard South. Steve Marcus / Las Vegas Sun / Reuters
Police run to cover at the scene of a shooting near the Mandalay Bay resort and casino on the Las Vegas Strip, Sunday, Oct. 1, 2017, in Las Vegas. Multiple victims were being transported to hospitals after a shooting late Sunday at a music festival on the Las Vegas Strip. (AP Photo/John Locher)
Medics treat the wounded as Las Vegas police respond during an active shooter situation on the Las Vegas Strip. Chase Stevens / Las Vegas Review-Journal via AP
Police officers and medical personnel stand at the scene of a shooting near the Mandalay Bay resort and casino on the Las Vegas Strip. John Locher / AP Photo
Police officers stand at the scene of a shooting near the Mandalay Bay resort and casino on the Las Vegas Strip. John Locher / AP Photo
A police officer takes cover behind a truck at the scene of a shooting near the Mandalay Bay resort and casino on the Las Vegas Strip. John Locher / AP Photo
Police officers advise people to take cover near the scene of a shooting near the Mandalay Bay resort and casino on the Las Vegas Strip, Sunday, Oct. 1, 2017, in Las Vegas. (AP Photo/John Locher)
A police officer takes cover behind a police vehicle during a shooting near the Mandalay Bay resort and casino on the Las Vegas Strip. John Locher / AP Photo
Police officers enter the Mandalay Bay resort and casino during a shooting near the Mandalay Bay resort and casino on the Las Vegas Strip. John Locher / AP Photo
Police officers take cover near the scene of a shooting near the Mandalay Bay resort and casino on the Las Vegas Strip. John Locher / AP Photo
A police officer runs along a sidewalk near a shooting near the Mandalay Bay resort and casino on the Las Vegas Strip. John Locher / AP Photo
People scramble for cover at the Route 91 Harvest country music festival after gunfire was heard on October 1, 2017 in Las Vegas, Nevada. David Becker / Getty Images
Festival goers run for their lives. David Becker / Getty Images
Las Vegas police stand guard along the streets near the concert. David Becker / Getty Images
A body is covered with a sheet in the intersection of Tropicana Avenue and Las Vegas Boulevard South after a mass shooting at a music festival on the Las Vegas Strip in Las Vegas. Steve Marcus / Las Vegas Sun / Reuters
Las Vegas Metro Police officer stands by at a staging area in the junction of Tropicana Avenue and Las Vegas Boulevard South. Steve Marcus / Las Vegas Sun / Reuters
Police run to cover at the scene of a shooting near the Mandalay Bay resort and casino on the Las Vegas Strip, Sunday, Oct. 1, 2017, in Las Vegas. Multiple victims were being transported to hospitals after a shooting late Sunday at a music festival on the Las Vegas Strip. (AP Photo/John Locher)
Medics treat the wounded as Las Vegas police respond during an active shooter situation on the Las Vegas Strip. Chase Stevens / Las Vegas Review-Journal via AP
Police officers and medical personnel stand at the scene of a shooting near the Mandalay Bay resort and casino on the Las Vegas Strip. John Locher / AP Photo
Police officers stand at the scene of a shooting near the Mandalay Bay resort and casino on the Las Vegas Strip. John Locher / AP Photo
A police officer takes cover behind a truck at the scene of a shooting near the Mandalay Bay resort and casino on the Las Vegas Strip. John Locher / AP Photo
Police officers advise people to take cover near the scene of a shooting near the Mandalay Bay resort and casino on the Las Vegas Strip, Sunday, Oct. 1, 2017, in Las Vegas. (AP Photo/John Locher)
A police officer takes cover behind a police vehicle during a shooting near the Mandalay Bay resort and casino on the Las Vegas Strip. John Locher / AP Photo
Police officers enter the Mandalay Bay resort and casino during a shooting near the Mandalay Bay resort and casino on the Las Vegas Strip. John Locher / AP Photo
Police officers take cover near the scene of a shooting near the Mandalay Bay resort and casino on the Las Vegas Strip. John Locher / AP Photo
A police officer runs along a sidewalk near a shooting near the Mandalay Bay resort and casino on the Las Vegas Strip. John Locher / AP Photo