Here's what we know about the victims of the Las Vegas shooting

At least 50 people have died in a mass shooting in Las Vegas at a country music festival Sunday night, and details are slowly emerging about the victims.

One was an off-duty police officer from Bakersfield, according to the Las Vegas Metropolitan Police Department (LVMPD). His name has not yet been released while police notifies his family.

Two other off-duty officers were among the more than 400 transported to hospitals, police said. One is in stable condition after surgery, and the other's injuries weren't life-threatening, police said.

"The identification process of all of the injured and the deceased will take time, so authorities are asking the public for patience," LVMPD said in a press release Monday morning.

The gunman, identified as 64-year-old Stephen Paddock, opened fire from the 32nd floor of the Mandalay Bay Resort and Casino with an automatic rifle, police said. Police said they found him dead with at least 10 rifles in his hotel room.

Many of the Route 91 Harvest festival's approximately 22,000 attendees were young people, including families with kids. Country star Jason Aldean was onstage performing his headliner set to close the three-day festival when Paddock opened fire.

Police said family members could call 1-866-535-5654 if they are looking for missing loved ones.

The city of Las Vegas also set up a family reunification center and urged people to donate blood to help the victims.

While police secured the area, busloads of people were transported to the Thomas & Mack Center at the University of Nevada, Las Vegas, campus, where the Las Vegas Review Journal reported they were patted down before entering.

Officials expect the death toll to rise.

Clark County Sheriff Joseph Lombardo said at a news conference that police were still finding people who had taken cover during the shooting as the sun rose on Monday.

"It's going to take time for us to get through the evacuation phase," he said.

This story is developing. Refresh for updates.