01 / 21

Las Vegas Shooting

A police officer takes cover behind a police vehicle during 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)

02 / 21

Las Vegas Shooting

A police officer runs along a sidewalk near 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)

03 / 21

Las Vegas Shooting

Police officers 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)

04 / 21

Las Vegas Shooting

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)

05 / 21

Las Vegas Shooting

A wounded person is walked in on a wheelbarrow as Las Vegas police respond during an active shooter situation on the Las Vegas Stirp in Las Vegas Sunday, Oct. 1, 2017. Multiple victims were being transported to hospitals after a shooting late Sunday at a music festival on the Las Vegas Strip. (Chase Stevens/Las Vegas Review-Journal via AP)

06 / 21

Vegas Strip Shooting

Medics treat the wounded as Las Vegas police respond during an active shooter situation on the Las Vegas Stirp in Las Vegas Sunday, Oct. 1, 2017. Multiple victims were being transported to hospitals after a shooting late Sunday at a music festival on the Las Vegas Strip. (Chase Stevens/Las Vegas Review-Journal via AP)

07 / 21

Las Vegas Shooting

People assist a wounded woman at the Tropicana during an active shooter situation on the Las Vegas Stirp in Las Vegas Sunday, Oct. 1, 2017. Multiple victims were being transported to hospitals after a shooting late Sunday at a music festival on the Las Vegas Strip. (Chase Stevens/Las Vegas Review-Journal via AP)

08 / 21

Las Vegas Shooting

Police officers stand at the scene of a shooting near the Mandalay Bay resort and casino on the Las Vegas Strip, Monday, Oct. 2, 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)

09 / 21

Las Vegas Shooting

A woman sits on a curb at the scene of a shooting outside of a music festival along the Las Vegas Strip, Monday, Oct. 2, 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)

10 / 21

Las Vegas Shooting

A wounded woman is moved outside the Tropicana during an active shooter situation on the Las Vegas Strip in Las Vegas Sunday, Oct. 1, 2017. Multiple victims were being transported to hospitals after a shooting late Sunday at a music festival on the Las Vegas Strip. (Chase Stevens/Las Vegas Review-Journal via AP)

11 / 21

Las Vegas Shooting

Las Vegas police respond during an active shooter situation on the Las Vegas Strip near Tropicana Avenue in Las Vegas Sunday, Oct. 1, 2017. Multiple victims were being transported to hospitals after a shooting late Sunday at a music festival on the Las Vegas Strip. (Chase Stevens/Las Vegas Review-Journal via AP)

12 / 21

Las Vegas Shooting

A wounded woman is moved outside the Tropicana during an active shooter situation on the Las Vegas Strip in Las Vegas Sunday, Oct. 1, 2017. Multiple victims were being transported to hospitals after a shooting late Sunday at a music festival on the Las Vegas Strip. (Chase Stevens/Las Vegas Review-Journal via AP)

13 / 21

Las Vegas Shooting

People are searched by Las Vegas police at the Tropicana Las Vegas during an active shooter situation on the Las Vegas Strip on Sunday, Oct. 1, 2017. Multiple victims were being transported to hospitals after a shooting late Sunday at a music festival on the Las Vegas Strip. (Chase Stevens/Las Vegas Review-Journal via AP)

14 / 21

Las Vegas Shooting

A man waits during lockdown at the Tropicana Las Vegas during an active shooter situation on the Las Vegas Strip Sunday, Oct. 1, 2017. Multiple victims were being transported to hospitals after a shooting late Sunday at a music festival on the Las Vegas Strip. (Chase Stevens/Las Vegas Review-Journal via AP)

15 / 21

Las Vegas Shooting

Drapes billow out of broken windows at the Mandalay Bay resort and casino Monday, Oct. 2, 2017, on the Las Vegas Strip following a deadly shooting at a music festival in Las Vegas. A gunman was found dead inside a hotel room. (AP Photo/John Locher)

16 / 21

Las Vegas Shooting

Drapes billow out of broken windows at the Mandalay Bay resort and casino Monday, Oct. 2, 2017, on the Las Vegas Strip following a deadly shooting at a music festival in Las Vegas. A gunman was found dead inside a hotel room. (AP Photo/John Locher)

17 / 21

APTOPIX Las Vegas Shooting

Las Vegas police sweep through a convention center area during a lockdown Monday, Oct. 2, 2017, at the Tropicana Las Vegas following an active shooter situation on the Las Vegas Strip. Multiple victims were transported to hospitals after a deadly shooting late Sunday at a music festival on the Las Vegas Strip. (Chase Stevens/Las Vegas Review-Journal via AP)

18 / 21

Las Vegas Shooting

People load into buses destined to different Strip Casinos following a mass shooting at the Route 91 music festival along the Las Vegas Strip, Monday, Oct. 2, 2017. UNLV's Thomas & Mack Center was opened as a place of refuge. (Yasmina Chavez/Las Vegas Sun via AP)

19 / 21

Las Vegas Shooting

A group of women wait for their ride outside the Thomas & Mack center, which served as a refuge, following a mass shooting at the Route 91 music festival along the Las Vegas Strip, Monday, Oct. 2, 2017, in Las Vegas. (Yasmina Chavez/Las Vegas Sun via AP)

20 / 21

Las Vegas Shooting

Melissah Burke and her husband Stephen, of Seattle, walk along the Las Vegas Strip near Mandalay Bay hotel and casino Monday, Oct. 2, 2017, in Las Vegas. The couple, who were attending the music festival last night where a mass shooting occurred, found refuge in a nearby apartment and casino. (AP Photo/Ronda Churchill)

21 / 21

APTOPIX Las Vegas Shooting

A body is covered with a sheet after a mass shooting in which dozens were killed at a music festival on the Las Vegas Strip on Sunday, Oct. 1, 2017. (Steve Marcus/Las Vegas Sun via AP)